View source for Second Happy Time

{{Short description|Period of naval battles during the Second World War}}
{{Use American English|date=November 2012}}
{{Use dmy dates|date=November 2021}}
[[File:Allied tanker torpedoed.jpg|thumb|upright=1.5|''Dixie Arrow'' torpedoed off [[Cape Hatteras]] by {{GS|U-71|1940|2}}, {{nowr|26 March 1942}}]]
{{Campaignbox Atlantic Campaign}}
The '''Second Happy Time''' ({{Langx|de|Zweite glückliche Zeit}}; officially  '''Operation Paukenschlag''' ("'''Operation Drumbeat'''"), and also known among German [[submarine]] commanders as the "'''American Shooting Season'''"<ref>Miller, Nathan: ''War at Sea: A Naval History of World War II''. Oxford University Press, 1997, p. 295. {{ISBN|0-19-511038-2}}</ref>) was a phase in the [[Battle of the Atlantic]] during which [[Axis powers|Axis]] submarines attacked [[merchant shipping]] and [[Allies of World War II|Allied]] naval vessels along the east coast of North America. The [[First Happy Time]] was in 1940–1941 in the North Atlantic and North Sea. [[Adolf Hitler]] and [[Benito Mussolini]] declared war on the United States on 11 December 1941, and as a result their navies could begin the Second Happy Time.<ref>Duncan Redford; Philip D. Grove (2014). The Royal Navy: A History Since 1900. I.B. Tauris. p. 182</ref>

The Second Happy Time lasted from January 1942 to about August of that year and involved several German naval operations, including [[Operation Neuland]]. German submariners named it the "Happy Time" or the "Golden Time," as defense measures were weak and disorganized,<ref name=Gannon/>{{rp|p292}} and the [[U-boat]]s were able to inflict massive damage with little risk. During this period, Axis submarines sank 609 ships totaling 3.1 million tons, against a loss of only 22 U-boats. This led to the loss of thousands of lives, mainly those of merchant mariners. Although fewer than the losses during the [[Atlantic U-boat campaign of World War I#1917|1917 campaign]] of the [[First World War]],<ref>Churchill (1950): p. 111</ref> those of this period equaled roughly one quarter of all ships sunk by U-boats during the entire [[World War II|Second World War]].

Historian [[Michael Gannon (historian)|Michael Gannon]] called it "America's Second [[Attack on Pearl Harbor|Pearl Harbor]]" and placed the blame for the nation's failure to respond quickly to the attacks on the inaction of Admiral [[Ernest King|Ernest J. King]], commander-in-chief of the [[United States Navy]] (USN). Because King also refused British offers to provide the US navy with their own ships, the belated institution of a [[convoy]] system was in large part due to a severe shortage of suitable escort vessels, without which convoys were seen as actually more vulnerable than lone ships.<ref>Timothy J. Ryan and Jan M. Copes ''To Die Gallantly – The Battle of the Atlantic'', 1994 Westview Press, Chapter 7.</ref>

==Background==
===German intentions===
Upon [[German declaration of war against the United States (1941)|Germany's declaration of war on the United States]] on 11 December 1941 just after the [[attack on Pearl Harbor]], the US was, on paper at least, in a fortunate position. Where the other combatants on the Allied side had already lost thousands of trained sailors and airmen, and were experiencing shortages of ships and aircraft, the US was at full strength (save for its recent losses at Pearl Harbor). The US had the opportunity to learn about modern naval warfare by observing the conflicts in the [[North Sea]] and the Mediterranean, and through a close relationship with the United Kingdom. The USN had already gained significant experience in countering U-boats in the Atlantic, particularly from April 1941 when President [[Franklin D. Roosevelt]] extended the "[[Pan-American Security Zone]]" east almost as far as [[Iceland]]. The United States had massive manufacturing capacity and a favorable geographical position from a defensive point of view: the [[New York Harbor|port of New York]], for example, was 3,000 miles to the west of the [[U-boat]] bases in [[Brittany]].

U-boat commander ''Vizeadmiral'' [[Karl Dönitz]] saw the entry of the US into the war as a golden opportunity to strike heavy blows in the [[tonnage war]] and Hitler ordered an assault on America on 12 December 1941. The standard [[Type VII submarine]] had insufficient range to patrol off the coast of North America (although, in due time, Type VII submarines were successfully able to patrol off the eastern seaboard of North America, due to refueling, rearming, and resupply logistical support by [[Type XIV submarine|Type XIV]] [[submarine tender]]); the only suitable weapons he had on hand were the larger [[Type IX submarine|Type IX]].<ref>Blair p. 438</ref> These were less maneuverable and slower to submerge, making them much more vulnerable than the Type VIIs. They were also fewer in number.

===American deficiencies===
[[File:Noblackout.gif|thumb|Animation simulating a tanker silhouetted against lights of a city. When partial blackouts were introduced towards the middle of 1942, [[skyglow]] continued to be a problem in coastal cities.]]
The American response in early 1942 was hampered by poor organization and doctrine, and a lack of [[anti-submarine warfare]] (ASW) aircraft, ships, and personnel.

The USN entered the war without the equivalent of the British {{sclass|Black Swan|sloop|0}} [[Sloop-of-war|sloop]] or the {{sclass2|River|frigate}} despite previous involvement in the Atlantic (see {{USS|Reuben James|DD-245|6}}.) The massive new naval construction program prioritized other types of ships. Fleet destroyers did not have the qualities for ASW; the ideal ASW escort had relatively low speed; carried a large number of depth charges; was highly maneuverable; and had long endurance.{{citation needed|date=January 2022}} The 50 World War I-era [[destroyer]]s transferred to Britain in the 1941 [[Destroyers for Bases Agreement]] would have been poor ASW escorts, even had they been retained, due to poor maneuverability.<ref>Gannon 1990. p. 238</ref>

The USN had some destroyers available on the east coast at the time of the first attacks. It had previously recalled at least 25 Atlantic Convoy Escort Command Destroyers, including seven at anchor in [[New York Harbor]]. It initially refused to use them as escorts even as losses mounted.<ref name=Gannon/>{{rp|p238}} When the first destroyers were finally released, their employment was hampered by poor doctrine. They were assigned to offensive patrols rather than escorting convoys due to public and political pressure. As late as March, USN escort doctrine was aggressive with an emphasis on destroying attackers, rather than stopping losses.<ref>Milner (2011): chapter 4 ("In the absence of proper escort vessels...")</ref>{{page needed|date=February 2022}} The option of pressing small civilian ships into service as rudimentary convoy escorts in early 1942 was not exercised.<ref name="milner_2011_ch4_ncs">Milner (2011): chapter 4 ("The establishment of a convoy system...")</ref>{{page needed|date=February 2022}}

Even if escorts had been available, the USN was unprepared to perform "Naval Control of Shipping" (NCS), the control and tracking of shipping (in convoy or sailing independently), although it had already received the reference material from Canada. Without escorts, the US could not take advantage of the existing Allied NCS. For shipping in the western Atlantic north of the equator, NCS was handled by the [[Royal Canadian Navy]] (RCN) since the start of the war; the RCN only passed the responsibility to the USN in July 1942.<ref name="milner_2011_ch4_ncs"/>

Operationally, the USN's ASW effort was fragmented. In theory, Admiral King was responsible for coordinating all ASW activities, including the development of doctrine. In practice, King's many other responsibilities prevented him from doing an adequate job. Therefore, the three Atlantic operational commands – the Atlantic Fleet, the [[Eastern Sea Frontier]], and the [[Sea Frontier|Gulf Sea Frontier]] – were left to develop their own ASW tactics individually.<ref name="milner_2011_ch4_us_asw">Milner (2011): chapter 4 ("The U-boat campaign in American waters...")</ref>{{page needed|date=February 2022}} The issue was not resolved until May 1943 with the formation of the [[United States Tenth Fleet]].<ref name="milner_2011_ch7_us10">Milner (2011): chapter 7 ("His moves did not go unnoticed.")</ref>{{page needed|date=February 2022}}

British experience in the first two years of World War II, which included the massive losses incurred to their shipping during the [[First Happy Time]] confirmed that ships sailing in [[convoy]] – with or without escort – were far safer than ships sailing alone. The British recommended that merchant ships should avoid obvious standard routings wherever possible; navigational markers, lighthouses, and other aids to the enemy should be removed, and a strict coastal [[Blackout (wartime)|blackout]] be enforced. In addition, any available air and sea forces should perform daylight patrols to restrict the U-boats' flexibility. For several months, none of the recommendations were followed. Coastal shipping continued to sail along marked routes and burn normal navigation lights. Boardwalk communities ashore were only 'requested' to 'consider' turning their illuminations off on 18 December 1941, but not in the cities; they did not want to offend the tourism, recreation and business sectors.<ref name=Gannon/> {{rp|p186}}

The primary target area was the Eastern Sea Frontier, commanded by Rear-Admiral [[Adolphus Andrews]] and covering the area from [[Maine]] to [[North Carolina]]. Andrews had practically no modern forces to work with: on the water he commanded seven [[United States Coast Guard|Coast Guard]] [[United States Coast Guard Cutter|cutters]], four converted yachts, three 1919-vintage [[patrol boat]]s, two [[gunboat]]s dating back to 1905, and four wooden [[submarine chaser]]s. About 100 aircraft were available, but these were short-range models only suitable for training. As a consequence of the traditionally antagonistic relationship between the USN and the [[United States Army Air Forces|Army Air Forces]], all larger aircraft remained under USAAF control, and in any case the USAAF was neither trained nor equipped for ASW.<ref name=Gannon/>{{rp|p182}}

== Campaign ==
=== Opening moves ===
Immediately after war was declared on the United States, Dönitz began to implement Operation Paukenschlag (often translated as "drumbeat" or "drumroll",<ref>Fairbank White, David – ''Bitter Ocean – The dramatic story of the Battle of the Atlantic 1939–1945'', 2006, Headline Publishing Group {{ISBN|978-0-7553-1089-0}}, p. 146</ref> and literally as "[[timpani]] beat"). Only six of the twenty operational Type IX boats were available, and one of those six encountered mechanical trouble. This left just five long-range submarines for the opening moves of the campaign.<ref>Blair pp. 438–441</ref>

Loaded with the maximum possible amounts of fuel, food and ammunition, the first of the five Type IXs left [[Lorient]] in France on 18 December 1941, the others following over the next few days. Each carried sealed orders to be opened after passing 20°W, which directed them to different parts of the North American coast. No charts or sailing directions were available: ''[[Kapitänleutnant]]'' [[Reinhard Hardegen]] of {{GS|U-123|1940|2}}, for example, was provided with two tourist guides to New York, one of which contained a fold-out map of the harbor.<ref name=Gannon>Michael Gannon, ''Operation Drumbeat: the dramatic true story of Germany's first U-boat attacks along the American coast in World War II'', 1990, Harper and Row publishers, {{ISBN|0-06-016155-8}}</ref>{{rp|p137}}

Each U-boat made routine signals on exiting the [[Bay of Biscay]], which were picked up by the British [[Y service]] and plotted in [[Rodger Winn]]'s London Submarine Tracking Room, which were then able to follow the progress of the Type IXs across the Atlantic, and cable an early warning to the RCN. Working on the slimmest of evidence, Winn correctly deduced the target area and passed a detailed warning to Admiral King,<ref>Fairbank White, p. 147</ref> of a "heavy concentration of U-boats off the North American seaboard", including the five boats already on station and further groups that were in transit, 21 U-boats in all. Rear-Admiral [[Edwin T. Layton]] of the US Combined Operations and Intelligence Center then informed the responsible area commanders, but little or nothing else was done.<ref>Gannon 1990. Chapter 9</ref>

On 12 January 1942, Admiral Andrews was warned that "three or four U-boats" were about to commence operations against coastal shipping (in fact, there were indeed three),<ref>Gannon 1990. p. 212</ref> but he refused to institute a convoy system on the grounds that this would only provide the U-boats with more targets.

When {{GS|U-123|1940|2}} sank the 9,500-ton Norwegian tanker ''Norness'' within sight of [[Long Island]] in the early hours of 14 January, no warships were dispatched to investigate, allowing the ''U-123'' to sink the 6,700-ton British tanker ''Coimbra'' off [[Sandy Hook, New Jersey|Sandy Hook]] on the following night before proceeding south towards [[New Jersey]]. By this time there were 13 destroyers idle in New York Harbor, yet none were employed to deal with the immediate threat, and over the following nights ''U-123'' was presented with a succession of easy targets, most of them burning navigation lamps. At times, ''U-123'' was operating in coastal waters that were so shallow that they barely allowed it to conceal itself, let alone evade a depth charge attack.

=== Operation Drumbeat ===
The first attack wave, Operation Drumbeat, consisted of five Type IX boats. Their first victory upon arriving in the coastal region of North America was the Canadian freighter ''Cyclops'', sunk on 12 January off [[Nova Scotia]]. According to Robert Fisher, 26 more ships were sunk in the following nine days.<ref name="fisher_oil_34">Fisher (1993): p. 34</ref> The boats cruised along the coast, safely submerged through the day, and surfacing at night to pick off merchant vessels outlined against the lights of the cities.
* [[Reinhard Hardegen]] in {{GS|U-123|1940|2}} sank seven ships totalling 46,744 tons before he ran out of torpedoes and returned to base;
* [[Ernst Kals]] in {{GS|U-130|1941|2}} sank six ships of 36,988 tons;
* [[Robert-Richard Zapp]] in {{GS|U-66|1940|2}} sank five ships of 33,456 tons;
* [[Heinrich Bleichrodt]] in {{GS|U-109|1940|2}} sank four ships of 27,651 tons; and
* [[Ulrich Folkers]] on his first patrol in {{GS|U-125|1940|2}} sank one 6,666-ton vessel, the ''West Ivis'' (he was criticized by Dönitz for his poor performance, although he would later win the [[Knight's Cross of the Iron Cross]]).<ref name=Gannon/>{{rp|p. 271}}

When the first wave of U-boats returned to port through the early part of February, Dönitz wrote that each commander "had such an abundance of opportunities for attack that he could not by any means utilize them all: there were times when there were up to ten ships in sight, sailing with all lights burning on peacetime courses."

The RCN immediately organized coastal convoys when Drumbeat began despite the difficulty in finding escorts. 37 ships were lost in January and February, and only 11 in March and April. The RCN noted that by March and April the U-boats preferred hunting in US waters.<ref name="fisher_oil_35">Fisher (1993): p. 35</ref>

===U-boats in the Caribbean and the Gulf of Mexico===

{{See also|Operation Neuland|Battle of the St. Lawrence}}
[[File:Pennsylvania Sun.jpg|thumb|The tanker ''[[SS Pennsylvania Sun|Pennsylvania Sun]]'' torpedoed by {{GS|U-571||2}} on 15 July 1942 (was saved and returned to service in 1943).]]
The second wave of Type IX boats had arrived in North American waters, and the third wave ([[Operation Neuland]]) had reached its patrol area off the oil ports of the [[Caribbean]]. With such easy pickings and all Type IX boats already committed, Dönitz began sending shorter-range Type VIIs to the US East Coast as well. This required extraordinary measures: cramming every conceivable space with provisions, some even filling the fresh water tanks with diesel oil, and crossing the Atlantic at very low speed on a single engine to conserve fuel.

In the United States there was still no concerted response to the attacks. Responsibility rested with Admiral King, but he was preoccupied with the Japanese onslaught in the [[Pacific War|Pacific]]. Admiral Andrews' North Atlantic Coastal Frontier was expanded to take in [[South Carolina]] and renamed the [[Eastern Sea Frontier]] (ESF), but most of the ships and aircraft needed remained under the command of Admiral [[Royal E. Ingersoll]], Commander-in-Chief, [[United States Fleet Forces Command|Atlantic Fleet]], who was often at sea and unavailable to make decisions. Rodger Winn's detailed weekly U-boat situation reports from the Submarine Tracking Room in London were available but ignored.{{citation needed|date=January 2022}} By April, Allied forces along the US east coast included 80 small patrol ships in the USN [[Eastern Sea Frontier]], 160 US aircraft, 24 RN ASW trawlers, and one British [[RAF Coastal Command|Coastal Command]] squadron. By British and Canadian standards these were enough to begin convoying, but no comprehensive convoy system was implemented that month.<ref name="milner_2011_ch4_april_convoys"/> Instead, on 1 April the US implemented a partial convoy system where convoys moved along the coast in short hops, moving during daytime and stopping in protected anchorages during nights; these were slow and ineffective.<ref name="churchill_1950_122-123">Churchill (1950): pp. 122–123</ref><ref name="milner_2011_ch4_april_convoys"/>

Coastal forces were reinforced from the [[Mid-Ocean Escort Force]] (MOEF) before March. The US contribution to the MOEF fell to part of one   group. Five RCN corvettes were withdrawn to escort the new [[BX convoys|Boston-Halifax convoys]], the first convoys along the American seaboard.<ref name="milner_2011_ch4_moef">Milner (2011): chapter 4 ("Mid-ocean escort forces were further squeezed...")</ref> In April, a [[Royal Navy]] (RN) group redeployed to the Caribbean to defend tankers.<ref name="milner_2011_ch4_april_convoys">Milner (2011): chapter 4 ("In the spring of 1942, the possibility of future problems...")</ref> The RCN attempted to reinforce the MOEF by using training ships in supporting roles.<ref name="milner_2011_ch4_moef"/>

Allied tanker losses were alarming. Losses along the North American coast and in the Caribbean accounted for most of the 73 American tankers lost in the first half of 1942, and 22 British tankers lost in March; three out of the four largest Canadian tankers were also lost from February to May. In March, British Prime Minister [[Winston Churchill]] urged the USN to organize coastal convoys, to little effect. The next month, British tankers from the Caribbean avoided the US coast and sailed east to [[Freetown]] in [[Africa]],<ref name="fisher_oil_34"/> while between 16 and 29 April the US ordered US and Caribbean coastal waters closed to commercial tanker movement.<ref name="fisher_oil_35"/> On 26 April, the US agreed to allow Britain to redeploy a MOEF group to establish Caribbean convoys, but the US refused to start its own Caribbean convoys or to provide escorts.<ref name="fisher_oil_36">Fisher (1993): p. 36</ref>

Eastern Canada was dependent on imported oil from the Gulf of Mexico and the Caribbean.<ref name="fisher_oil_33">Fisher (1993): p. 33</ref> The crisis led to gasoline rationing on 1 April, and the potential consequences of the US-ordered halt to tanker movements were severe. On 28 April, the RCN started [[ad hoc]] convoys to bring Canadian and Canadian-charted tankers trapped in the US and the Caribbean back to Halifax. On 1 May, the Government of Canada insisted that Canadian tankers be escorted, leading the RCN to organize formal convoys to the Caribbean through US coastal waters.<ref name="fisher_oil_35"/> The RCN had only enough escorts to run convoys from Halifax to Trinidad (coded as TH); the loss of supply from other regional suppliers had to be accepted.<ref name="fisher_oil_36"/> In July, Trinidad was replaced by Aruba to accommodate British tanker movement. From May to August, fourteen convoys – including 76 tankers and 4 million barrels of oil – were run without a single ship lost. The convoys were discontinued in August with the advent of the US's comprehensive convoying system.<ref name="fisher_oil_37">Fisher (1993): p. 37</ref> Canada also began convoys between Nova Scotia and [[Quebec City]] in May.<ref name="milner_2011_ch4_overextension"/>

The search for Allied tankers and the support of {{GS|U-459||2}}, a Type XIV, pushed the U-boat offensive into the Gulf of Mexico.<ref name="fisher_oil_36"/> On 21 April, ''U-459'' was 600 miles north-west of Bermuda; it refuelled fourteen U-boats through 6 May, including Type VIIs, headed for the Gulf and the Caribbean. In May, they sank 115 ships (of which 101 were steaming independently), about half being in the Gulf, with half of that tonnage being tankers. In June, they sank 122 ships, of which 108 were sailing independently. The Gulf Sea Frontier, formed in early February, had barely any resources and was ineffective.<ref name="milner_2011_ch4_gulf">Milner (2011): chapter 4 ("As U-boat attacks spilled into the Gulf of Mexico...")</ref>

=== US convoys arrive ===
The first organized US coastal convoy sailed on 14 May 1942 from [[Hampton Roads]] for [[Key West]]; convoys eventually extended to Halifax.<ref name="churchill_1950_122-123"/> The US sought another  15 to 20 corvettes from Britain.<ref>Milner (2011): chapter 4 ("By mid-May, with both the British and Canadians operating...")</ref> By this time, two British escort groups were already in the Caribbean and the MOEF was under strain. Nonetheless, Britain and Canada responded to US requests by reducing the size of the remaining MOEF groups. The MOEF and the RCN had no further slack. The RCN struggled to meet its commitments even with 90% of its escort fleet being operational, as opposed to being used for training or being refitted;<ref name="milner_2011_ch4_overextension">Milner (2011): chapter 4 ("While Hecht was chasing convoys in the mid-ocean...")</ref> the negative effects of this over-extension would be felt well into 1943.<ref name="milner_2011_ch5_overextension">Milner (2011): chapter 5 ("By late summer 1942, the RCN was over extended...")</ref>  By comparison the RN escort fleet was merely two-thirds operational.<ref name="milner_2011_ch4_overextension"/> The weakening of MOEF contributed to difficulties in the mid-Atlantic in August.<ref name="milner_2011_ch4_moef"/>

The US convoy system effectively brought the crisis to an end. By early-July most U-boats only operated along the perimeter of the Caribbean. German attention returned to the mid-Atlantic.<ref>Milner (2011): chapter 4 ("By early July, four U-boats were still slaughtering...")</ref>

== Propaganda ==
Popular alarm at the sinkings was dealt with by a combination of secrecy and misleading propaganda. The US Navy confidently announced that many of the U-boats would "never enjoy the return portion of their voyage"{{cn|date=July 2024}} but that unfortunately, details of the sunken U-boats could not be made public lest the information aid the enemy. All citizens who had witnessed the sinking of a U-boat were asked to help keep the secrets safe.{{cn|date=July 2024}}

==Losses==
===Allies===
[[File:Allied tanker torpedoed.jpg|thumb|SS ''Dixie Arrow'' torpedoed on 26 March 1942 south of [[Hatteras Island]] ]]
[[File:Benson3 big.jpg|thumb|SS ''Byron D. Benson'' torpedoed on 4 April 1942 east of [[Southern Shores, North Carolina]].]]
* 12 January – Canadian steamship [[SS Cyclops (1906)|''Cyclops'']] sunk by {{GS|U-123|1940|2}}<ref name="fisher_oil_34"/> (87 of 182 crew, gunners, and passengers were lost)<ref>Tennant (2001) p. 178</ref>
* 14 January – Panamanian tanker ''Norness'' sunk by {{GS|U-123|1940|2}} at {{coord|40.44|-70.91|type:event|display=inline|name=Norness sunk by U-123}}<ref name="cressman69">Cressman (2000) p. 69</ref>
* 18 January – US tanker ''Allan Jackson'' sunk by {{GS|U-66|1940|2}} at {{coord|35.95|-74.33|display=inline|type:event}} (23 of 35 crewmen perished)<ref name="cressman70">Cressman (2000) p. 70</ref>
* 18 January – US tanker ''Malay'' damaged by ''U-123'' at {{coord|35.42|-75.38|display=inline|type:event}} (5 crewmen perished)<ref name="cressman70"/>
* 19 January – US steamship ''City of Atlanta'' sunk by {{GS|U-123|1940|2}} at {{coord|35.70|-75.35|display=inline|type:event}} (43 of 46 crewmen perished)<ref name="cressman70"/>
* 19 January – Canadian steamship ''Lady Hawkins'' sunk by ''U-66'' at {{coord|35.0|-72.5|display=inline|type:event}}<ref name="cressman70"/> (251 of 322 crew, gunners, and passengers were lost)<ref>Tennant (2001) p. 57</ref>
* 22 January – US freighter ''Norvana'' sunk by ''U-123'' south of [[Cape Hatteras]] (no survivors)<ref name="cressman71">Cressman (2000) p. 71</ref>
* 23 January – US collier ''Venore'' sunk by ''U-66'' at {{coord|35.83|-75.33|display=inline|type:event}} (17 of 41 crewmen perished)<ref name="cressman71"/>
* 25 January – US tanker ''Olney'' damaged by {{GS|U-125|1940|2}} at {{coord|37.92|-74.93|display=inline|type:event}}<ref name="cressman71"/>
* 26 January – US freighter ''West Ivis'' sunk by ''U-125'' (all 45 crewmen perished)<ref name="cressman71"/>
* 27 January – US tanker ''Francis E. Powell'' sunk by ''U-130'' at {{coord|37.75|-74.88|display=inline|type:event}} (4 of 32 crewmen perished)<ref name="cressman72">Cressman (2000) p. 72</ref>
* 27 January – US tanker ''Halo'' damaged by ''U-130'' at {{coord|35.55|-75.33|display=inline|type:event}}<ref name="cressman72"/>
* 30 January – US tanker ''Rochester'' sunk by {{GS|U-106|1940|2}} at {{coord|37.17|-73.97|display=inline|type:event}} (3 of 32 crewmen perished)<ref name="cressman72"/>
* 31 January – US ''San Arcadio'' sunk by {{GS|U-107|1940|2}} at {{coord|38.17|-63.83|display=inline|type:event}}<ref name="cressman72"/>
* 31 January – US ''Tacoma Star'' sunk by ''U-109'' at {{coord|37.55|-69.35|display=inline|type:event}}<ref name="cressman72"/>
* 2 February – US tanker ''W.L. Steed'' sunk by {{GS|U-103|1940|2}} at {{coord|38.42|-72.72|display=inline|type:event}} (34 of 38 crewmen perished)<ref name="cressman73">Cressman (2000) p. 73</ref>
* 3 February – Panamanian freighter ''San Gil'' sunk by ''U-103'' at {{coord|38.08|-74.67|display=inline|type:event}} (2 of 40 crewmen perished)<ref name="cressman73"/>
* 4 February – US tanker ''India Arrow'' sunk by ''U-103'' at {{coord|38.80|-73.67|display=inline|type:event}} (26 of 38 crewmen perished)<ref name="cressman73"/>
* 5 February – US tanker ''China Arrow'' sunk by ''U-103'' at {{coord|38.73|-73.30|display=inline|type:event}}<ref name="cressman73"/>
* 6 February – US freighter ''Major Wheeler'' sunk by ''U-107'' (all 35 crewmen perished)<ref name="cressman74">Cressman (2000) p. 74</ref>
* 8 February – British freighter ''Ocean Venture'' sunk by ''U-108'' at {{coord|37.08|-74.75|display=inline|type:event}}<ref name="cressman74"/> (31 of 45 crew, and gunners were lost)<ref>Tennant (2001) p. 198</ref>
* 10 February – Canadian tanker ''Victolite'' sunk by {{GS|U-564||2}} at {{coord|36.20|-67.23|display=inline|type:event}}<ref name="cressman74"/> (all 47 crew and gunners were lost)<ref>Tennant (2001) p. 188</ref>
* 15 February – Brazilian steamship ''Buarque'' sunk by ''U-432'' at {{coord|36.58|-75.33|display=inline|type:event}}<ref name="cressman75">Cressman (2000) p. 75</ref>
* 18 February – Brazilian tanker ''Olinda'' sunk by ''U-432'' at {{coord|37.5|-75.0|display=inline|type:event}}<ref name="cressman76">Cressman (2000) p. 76</ref>
* 19 February – US tanker ''Pan Massachusetts'' sunk by {{GS|U-128|1941|2}} at {{coord|28.45|-80.13|display=inline|type:event}} (20 of 38 crewmen perished)<ref name="cressman76"/>
* 20 February – US freighter ''Azalea City'' sunk by ''U-432'' at {{coord|38.0|-73.0|display=inline|type:event}} (All 38 crewmen perished)<ref name="cressman77">Cressman (2000) p. 77</ref>
* 21 February – US tanker ''Republic'' sunk by {{GS|U-504||2}} at {{coord|27.08|-80.25|display=inline|type:event}} (5 of 29 crewmen perished)<ref name="cressman77"/>
* 22 February – US tanker ''Cities Service Empire'' sunk by ''U-128'' at {{coord|28.00|-80.27|display=inline|type:event}} (14 of 50 crewmen perished)<ref name="cressman77"/>
* 22 February – US tanker ''W.D. Anderson'' sunk by ''U-504'' at {{coord|27.15|-79.93|display=inline|type:event}} (35 of 36 crewmen perished)<ref name="cressman77"/>
* 26 February – US bulk carrier ''Marore'' sunk by ''U-432'' at {{coord|35.55|-74.97|display=inline|type:event}}<ref name="cressman79">Cressman (2000) p. 79</ref>
* 26 February – US tanker ''R.P. Resor'' sunk by ''U-578'' at {{coord|39.78|-73.43|display=inline|type:event}} (47 of 49 crewmen perished)<ref name="cressman79"/>
* 28 February – US destroyer {{USS|Jacob Jones|DD-130|2}} sunk by ''U-578'' at {{coord|38.70|-74.65|display=inline|type:event}}<ref name="cressman79"/>
* 7 March – US freighter ''Barbara'' sunk by ''U-126'' at {{coord|20.00|-73.93|display=inline|type:event}}<ref name="cressman81">Cressman (2000) p. 81</ref>
* 7 March – US freighter ''Cardonia'' sunk by ''U-126'' at {{coord|19.88|-73.45|display=inline|type:event}}<ref name="cressman81"/>
* 7 March – Brazilian steamship ''Arabutan'' sunk by {{GS|U-155|1941|2}} at {{coord|35.25|-73.92|display=inline|type:event}}<ref name="cressman81"/>
* 9 March – Brazilian steamship ''Cayru'' sunk by {{GS|U-94|1940|2}} at {{coord|39.16|-72.03|display=inline|type:event}}<ref name="cressman81"/>
* 10 March – US tanker ''Gulftrade'' sunk by ''U-588'' at {{coord|39.84|-73.87|display=inline|type:event}}<ref name="cressman82">Cressman (2000) p. 82</ref>
* 11 March – US freighter ''Texan'' sunk by ''U-126'' at {{coord|21.53|-76.40|display=inline|type:event}}<ref name="cressman82"/>
* 11 March – US freighter ''Caribsea'' sunk by ''U-158'' at {{coord|34.67|-76.16|display=inline|type:event}}<ref name="cressman82"/>
* 12 March – US tanker ''John D. Gill'' sunk by ''U-158'' at {{coord|35.92|-77.65|display=inline|type:event}} (4 crewmen perished)<ref name="cressman82"/>
* 12 March – US freighter ''Olga'' sunk by ''U-126'' at {{coord|23.65|-77.00|display=inline|type:event}}<ref name="cressman82"/>
* 12 March – US freighter ''Colabee'' damaged by ''U-126'' at {{coord|22.23|-77.58|display=inline|type:event}}<ref name="cressman82"/>
* 13 March – US schooner ''Albert F. Paul'' sunk by ''U-332'' at {{coord|26.0|-72.0|display=inline|type:event}} (no survivors)<ref name="cressman82"/>
* 13 March – Chilean freighter ''Tolten'' sunk by {{GS|U-404||2}} at {{coord|40.16|-73.84|display=inline|type:event}} (15 of 16 crewmen perished)<ref name="cressman82"/>
* 14 March – US collier ''Lemuel Burrows'' sunk by ''U-404'' at {{coord|39.20|-74.27|display=inline|type:event}}<ref name="cressman82"/>
* 15 March – US tanker ''Ario'' sunk by ''U-158'' at {{coord|34.33|-76.65|display=inline|type:event}} (7 of 36 crewmen perished)<ref name="cressman82"/>
* 15 March – US tanker ''Olean'' sunk by ''U-158'' at {{coord|34.40|-76.48|display=inline|type:event}}<ref name="cressman82"/>
* 16 March – US tanker ''Australia'' sunk by ''U-332'' at {{coord|35.12|-75.37|display=inline|type:event}}<ref name="cressman82"/>
* 16 March – British tanker ''[[MV San Demetrio|San Demetrio]]'' sunk by ''U-404'' at {{coord|37.05|-73.84|display=inline|type:event}}<ref name="cressman83">Cressman (2000) p. 83</ref> (19 of 51 crew, and gunners were lost)<ref>Tennant (2001) p. 110</ref>
* 17 March – US tanker ''Acme'' damaged by {{GS|U-124|1940|2}} at {{coord|35.10|-76.67|display=inline|type:event}}<ref name="cressman83"/>
* 17 March – Greek freighter ''Kassandra Louloudi'' sunk by ''U-124'' four mile off Diamond Shoals gas buoy<ref name="cressman83"/>
* 17 March – Honduran freighter ''Ceiba'' sunk by ''U-124'' at {{coord|35.72|-73.82|display=inline|type:event}}<ref name="cressman83"/>
* 18 March – US tanker {{SS|E.M. Clark||2}} sunk by ''U-124'' at {{coord|34.84|-75.58|display=inline|type:event}}<ref name="cressman83"/>
* 18 March – US tanker ''Papoose'' sunk by ''U-124'' at {{coord|34.28|-76.65|display=inline|type:event}}<ref name="cressman83"/>
* 18 March – US tanker ''W.E. Hutton'' sunk by ''U-332'' at {{coord|34.08|-76.67|display=inline|type:event}} (13 of 36 crewmen perished)<ref name="cressman83"/>
* 19 March – US freighter ''Liberator'' sunk by ''U-332'' at {{coord|35.08|-75.50|display=inline|type:event}} (5 crewmen perished)<ref name="cressman83"/>
* 20 March – US tanker ''Oakmar'' sunk by ''U-71'' at {{coord|36.35|-68.84|display=inline|type:event}} (6 of 36 crewmen perished)<ref name="cressman83"/>
* 21 March – US tanker ''Esso Nashville'' sunk by ''U-124'' at {{coord|33.58|-77.37|display=inline|type:event}}<ref name="cressman83"/>
* 21 March – US tanker ''Atlantic Sun'' damaged by ''U-124''<ref name="cressman83"/>
* 22 March – US tanker ''Naeco'' sunk by ''U-124'' at {{coord|33.98|-76.67|display=inline|type:event}} (24 of 39 crewmen perished)<ref name="cressman83"/>
* 25 March – Dutch tanker ''Ocana'' sunk by {{GS|U-552||2}} at {{coord|42.60|-64.42|display=inline|type:event}}<ref name="cressman83"/>
* 26 March – US [[Q-ship]] {{USS|Atik|AK-101|6}} sunk by ''U-123'' at {{coord|36.0|-70.0|display=inline|type:event}} (All 139 crewmen perished)<ref name="cressman84">Cressman (2000) p. 84</ref>
* 26 March – US tanker ''[[SS Dixie Arrow|Dixie Arrow]]'' sunk by ''U-71'' at {{coord|34.98|-75.55|display=inline|type:event}} (11 of 33 crewmen perished)<ref name="cressman84"/>
* 26 March – Panamanian tanker ''Equipoise'' sunk by ''[[German submarine U-160 (1941)|U-160]]'' at {{coord|36.60|-74.75|display=inline|type:event}}<ref name="cressman84"/>
* 29 March – US steamship ''[[SS City of New York (1930)|City of New York]]'' sunk by ''U-160'' at {{coord|35.27|-74.42|display=inline|type:event}} (24 of 157 crewmen perished)<ref name="cressman84"/>
* 31 March – US tug ''Menominee'' and barges ''Allegheny'' and ''Barnegat'' sunk by {{GS|U-754||2}} at {{coord|37.57|-75.42|display=inline|type:event}}<ref name="cressman84"/>
* 31 March – US tanker ''Tiger'' sunk by ''U-754'' (1 of 43 crewmen perishes)<ref name="cressman85">Cressman (2000) p. 85</ref>
* 3 April – US freighter ''Otho'' sunk by ''U-754'' at {{coord|36.42|-71.95|display=inline|type:event}} (31 of 53 crewmen perished)<ref name="cressman85"/>
* 4 April – US tanker ''Byron D. Benson'' sunk by ''U-552'' at {{coord|36.13|-75.53|display=inline|type:event}} (9 of 37 crewmen perished)<ref name="cressman85"/>
* 6 April – US tanker ''Bidwell'' damaged by ''U-160'' {{coord|34.42|-75.95|display=inline|type:event}} (1 of 33 crewmen perishes)<ref name="cressman86">Cressman (2000) p. 86</ref>
* 7 April – Norwegian freighter ''Lancing'' sunk by ''U-552'' off Cape Hatteras<ref name="cressman86"/>
* 7 April – British tanker ''[[British Splendour (ship)|British Splendour]]'' sunk by ''U-552'' off Cape Hatteras<ref name="cressman86"/> (12 of 53 crew and gunners were lost)<ref name="Tennant 2001 p.44">Tennant (2001) p. 44</ref>
* 8 April – US tanker ''Oklahoma'' damaged by ''U-123'' at {{coord|31.30|-80.98|display=inline|type:event}} (19 of 37 crewmen perished)<ref name="cressman86"/>
* 8 April – US tanker ''Esso Baton Rouge'' damaged by ''U-123'' at {{coord|31.22|-80.08|display=inline|type:event}} (3 of 39 crewmen perished)<ref name="cressman86"/>
* 9 April – US freighter ''Esparta'' sunk by ''U-123'' {{coord|30.77|-81.18|display=inline|type:event}} (1 of 40 crewmen perishes)<ref name="cressman87">Cressman (2000) p. 87</ref>
* 9 April – US freighter ''Malchace'' sunk by ''U-160'' at {{coord|34.47|-75.93|display=inline|type:event}} (1 of 29 crewmen perished)<ref name="cressman87"/>
* 9 April – US tanker ''Atlas'' sunk by ''U-552'' at {{coord|34.45|-76.27|display=inline|type:event}} (2 of 34 crewmen perished)<ref name="cressman87"/>
* 9 April – tanker ''Tamaulipas'' sunk by ''U-552'' at {{coord|34.42|-76.00|display=inline|type:event}} (2 of 37 crewmen perished)<ref name="cressman87"/>
* 10 April – US tanker ''Gulfamerica'' sunk by ''U-123'' at {{coord|30.23|-81.30|display=inline|type:event}} (19 of 48 crewmen perished)<ref name="cressman87"/>
* 11 April – US tanker ''Harry F. Sinclair Jr.'' damaged by ''U-203'' at {{coord|34.42|-76.50|display=inline|type:event}} (10 of 36 crewmen perished)<ref name="cressman87"/>
* 11 April – British steamship ''Ulysses'' sunk by ''U-160'' at {{coord|34.38|-75.58|display=inline|type:event}}<ref name="cressman87"/> (all 290 crew, gunners, and passengers rescued)<ref>Tennant (2001) p. 175</ref>
* 12 April – Panamanian tanker ''Stanvac Melbourne'' sunk by ''U-203'' at {{coord|33.88|-77.48|display=inline|type:event}}<ref name="cressman87"/>
* 12 April – US freighter ''Leslie'' sunk by ''U-123'' at {{coord|28.62|-80.42|display=inline|type:event}} (3 of 32 crewmen perished)<ref name="cressman87"/>
* 14 April – British freighter ''Empire Thrush'' sunk by ''U-203'' at {{coord|35.20|-75.23|display=inline|type:event}}<ref name="cressman88">Cressman (2000) p. 88</ref> (all 55 crew and gunners rescued)<ref name="Tennant 2001 p.44"/>
* 14 April – US freighter ''Margaret'' sunk by {{GS|U-571||2}} at {{coord|35.20|-75.23|display=inline|type:event}} (All 29 crewmen perished)<ref name="cressman88"/>
* 15 April – US freighter ''Robin Hood'' sunk by ''U-575'' at {{coord|38.65|-66.63|display=inline|type:event}} (14 of 38 crewmen perished)<ref name="cressman88"/>
* 16 April – US freighter ''Alcoa Guide'' sunk by ''U-123'' at {{coord|35.57|-70.13|display=inline|type:event}} (6 of 34 crewmen perished)<ref name="cressman88"/>
* 17 April – Argentine tanker ''Victoria'' damaged by {{GS|U-201||2}} at {{coord|36.68|-68.80|display=inline|type:event}}<ref name="cressman88"/>
* 18 April – US tanker ''Axtell J. Byles'' damaged by ''U-136'' at {{coord|35.53|-75.32|display=inline|type:event}}<ref name="cressman89">Cressman (2000) p. 89</ref>
* 19 April – US freighter ''Steel Maker'' sunk by ''U-136'' at {{coord|33.08|-70.60|display=inline|type:event}} (1 of 45 crewmen perished)<ref name="cressman89"/>
* 20 April – US freighter ''West Imboden'' sunk by ''U-752'' at {{coord|41.23|-65.90|display=inline|type:event}}<ref name="cressman89"/>
* 21 April – US freighter ''Pipestone County'' sunk by ''U-576'' at {{coord|37.58|-66.33|display=inline|type:event}}<ref name="cressman89"/>
* 21 April – US freighter ''San Jacinto'' sunk by ''U-201'' at {{coord|31.16|-70.75|display=inline|type:event}} (14 of 183 crewmen perished)<ref name="cressman89"/>
* 29 April – US tanker ''Mobiloil'' sunk by ''U-108'' at {{coord|26.16|-66.25|display=inline|type:event}}<ref name="cressman90">Cressman (2000) p. 90</ref>
* 29 April – US tanker ''Federal'' sunk by {{GS|U-507||2}} at {{coord|21.22|-76.08|display=inline|type:event}} (5 of 33 crewmen perished)<ref name="cressman90"/>
* 2 May – US armed yacht {{USS|Cythera|PY-26|2}} sunk by {{GS|U-402||2}} off North Carolina (66 of 68 crewmen perished)<ref name="cressman89"/>
* 4 May – US tanker ''Norlindo'' sunk by ''U-507'' at {{coord|24.95|-84.00|display=inline|type:event}} (5 of 28 crewmen perished)<ref name="cressman91">Cressman (2000) p. 91</ref>
* 4 May – US tanker {{SS|Munger T. Ball||2}} sunk by ''U-507'' at {{coord|25.28|-83.95|display=inline|type:event}} (30 of 34 crewmen perished)<ref name="cressman91"/>
* 4 May – US tanker ''Joseph M. Cudahy'' sunk by ''U-507'' at {{coord|25.95|-83.95|display=inline|type:event}} (27 of 37 crewmen perished)<ref name="cressman91"/>
* 4 May – US freighter ''Delisle'' damaged by {{GS|U-564||2}} at {{coord|27.03|-80.05|display=inline|type:event}} (2 of 36 crewmen perished)<ref name="cressman91"/>
* 5 May – US freighter ''Afoundria'' sunk by ''U-108'' at {{coord|20.0|-73.50|display=inline|type:event}}<ref name="cressman91"/>
* 5 May – US tanker ''Java Arrow'' damaged by {{GS|U-333||2}} at {{coord|27.50|-80.13|display=inline|type:event}} (2 of 47 crewmen perished)<ref name="cressman91"/>
* 6 May – US tanker ''Halsey'' sunk by ''U-333'' at {{coord|27.23|-80.05|display=inline|type:event}} (5 of 28 crewmen perished)<ref name="cressman92">Cressman (2000) p. 92</ref>
* 6 May – US freighter ''Alcoa Puritan'' sunk by ''U-507'' at {{coord|28.67|-88.37|display=inline|type:event}}<ref name="cressman92"/>
* 8 May – US freighter ''Ohioan'' sunk by ''U-564'' at {{coord|26.52|-79.97|display=inline|type:event}} (15 of 37 crewmen perished)<ref name="cressman93">Cressman (2000) p. 93</ref>
* 10 May – US tanker ''Aurora'' damaged by ''U-506'' at {{coord|28.58|-90.00|display=inline|type:event}} (1 of 50 crewmen perished)<ref name="cressman94">Cressman (2000) p. 94</ref>
* 12 May – US tanker ''Virginia'' sunk by ''U-507'' at {{coord|28.88|-89.48|display=inline|type:event}} (27 of 41 crewmen perished)<ref name="cressman94"/>
* 13 May – US tanker ''Gulfprince'' damaged by ''U-507'' at {{coord|28.53|-91.00|display=inline|type:event}}<ref name="cressman94"/>
* 13 May – US tanker ''Gulfpenn'' sunk by ''U-506'' at {{coord|28.48|-89.20|display=inline|type:event}} (13 of 38 crewmen perished)<ref name="cressman94"/>
* 13 May – US freighter ''David McKelvy'' sunk by ''U-506'' at {{coord|28.50|-89.92|display=inline|type:event}} (17 of 36 crewmen perished)<ref name="cressman94"/>
* 15 May – US freighter ''Nicarao'' sunk by ''U-751'' at {{coord|25.33|-74.32|display=inline|type:event}} (8 of 39 crewmen perished)<ref name="cressman95">Cressman (2000) p. 95</ref>
* 16 May – US tanker ''Sun'' damaged by ''U-506'' at {{coord|28.68|-90.32|display=inline|type:event}}<ref name="cressman95"/>
* 16 May – US tanker ''William C. McTarnahan'' damaged by ''U-506'' at {{coord|28.87|-90.33|display=inline|type:event}} (18 of 38 crewmen perished)<ref name="cressman95"/>
* 16 May – US tanker ''Gulfoil'' sunk by ''U-506'' at {{coord|28.68|-90.32|display=inline|type:event}} (21 of 40 crewmen perished)<ref name="cressman95"/>
* 19 May – US freighter ''Heredia'' sunk by ''U-506'' at {{coord|27.53|-91.00|display=inline|type:event}} (36 of 62 crewmen perished)<ref name="cressman96">Cressman (2000) p. 96</ref>
* 19 May – US freighter ''Ogontz'' sunk by ''U-103'' at {{coord|23.5|-86.62|display=inline|type:event}} (19 of 41 crewmen perished)<ref name="cressman96"/>
* 20 May – US tanker ''Halo'' sunk by ''U-506'' at {{coord|28.70|-90.13|display=inline|type:event}} (21 of 42 crewmen perished)<ref name="cressman96"/>
* 20 May – US freighter ''George Calvert'' sunk by ''U-752'' at {{coord|22.92|-84.43|display=inline|type:event}} (3 of 61 crewmen perished)<ref name="cressman96"/>
* 21 May – US freighter ''Plow City'' sunk by ''U-588'' at {{coord|39.13|-69.95|display=inline|type:event}} (1 of 30 crewmen perished)<ref name="cressman97">Cressman (2000) p. 97</ref>
* 26 May – US tanker [[SS Carrabulle|''Carrabulle'']] sunk by ''U-106'' at {{coord|26.15|-89.35|display=inline|type:event}} (22 of 40 crewmen perished)<ref name="cressman98">Cressman (2000) p. 98</ref>
* 26 May – US freighter ''Atenas'' damaged by ''U-106'' at {{coord|25.84|-89.08|display=inline|type:event}}<ref name="cressman98"/>
* 30 May – US freighter ''Alcoa Shipper'' sunk by {{GS|U-404||2}} at {{coord|37.82|-65.25|display=inline|type:event}} (7 of 32 crewmen perished)<ref name="cressman99">Cressman (2000) p. 99</ref>
* 1 June – US freighter ''West Notus'' sunk by ''U-404'' at {{coord|34.16|-68.33|display=inline|type:event}} (4 of 40 crewmen perished)<ref name="cressman99"/>
* 1 June – US freighter ''Hampton Roads'' sunk by ''U-106'' at {{coord|23.0|-85.7|display=inline|type:event}} (5 of 28 crewmen perished)<ref name="cressman100">Cressman (2000) p. 100</ref>
* 3 June – US freighter ''M.F. Elliott'' sunk by {{GS|U-502||2}} off the Florida Keys (13 of 45 crewmen perished)<ref name="cressman100"/>
* 10 June – US tanker ''Hagan'' sunk by ''U-157'' at {{coord|22.0|-77.5|display=inline|type:event}} (6 of 44 crewmen perished)<ref name="cressman103">Cressman (2000) p. 103</ref>
* 12 June – US tanker ''Cities Service Toledo'' sunk by ''U-158'' at {{coord|29.03|-91.98|display=inline|type:event}} (15 of 45 crewmen perished)<ref name="cressman103"/>

===Germany===
* {{GS|U-85|1941|2}}: sunk on 14 April by the destroyer {{USS|Roper|DD-147|6}} in position {{coord|35.92|-75.22|display=inline|type:event}} off [[Cape Hatteras]],<ref name="cressman88"/> the first sinking in US waters
* {{GS|U-352||2}}: sunk on 9 May by the cutter USCGC [[USCGC Icarus (WPC-110)|''Icarus'']] in position {{coord|34.20|-76.58|display=inline|type:event}} off Cape Hatteras<ref name="cressman94"/>
* {{GS|U-157|1941|2}}: sunk on 13 June by the cutter USCGC [[USCGC Thetis WPC-115|''Thetis'']] in position {{coord|24.22|-82.05|display=inline|type:event}} off [[Havana]], [[Republic of Cuba (1902–1959)|Cuba]]<ref name="cressman103"/>
* {{GS|U-158|1941|2}}: sunk on 30 June by a [[Martin PBM Mariner|Mariner]] aircraft (USN VP-74) in position {{coord|32.83|-67.47|display=inline|type:event}} west of [[Bermuda]]<ref name="cressman106">Cressman (2000) p. 106</ref>
* {{GS|U-215||2}}: sunk on 3 July by the Armed ASW Trawler HMS ''Le Tiger'' in position {{coord|41.48|-66.38|display=inline|type:event}} by depth charges
* {{GS|U-701||2}}: sunk on 7 July by a [[Lockheed Hudson]] aircraft in position {{coord|34.83|-74.92|display=inline|type:event}} off Cape Hatteras<ref name="cressman108">Cressman (2000) p. 108</ref>
* {{GS|U-153|1941|2}}: sunk on 13 July by the destroyer {{USS|Lansdowne|DD-486|6}} in position {{coord|9.93|-81.48|display=inline|type:event}} off [[Colón, Panama]]<ref name="cressman109">Cressman (2000) p. 109</ref>
* {{GS|U-576||2}}: sunk on 15 July by two [[Vought OS2U Kingfisher]] aircraft and ramming by the US motor vessel ''Unicoi'' in position {{coord|34.85|-75.37|display=inline|type:event}} off Cape Hatteras<ref name="cressman110">Cressman (2000) p. 110</ref>
* {{GS|U-166|1941|2}}: sunk on 30 July by the US Navy patrol craft, PC 566, in position {{coord|28.52|-90.75|display=inline|type:event}} in the Gulf of Mexico,<ref name="cressman112">Cressman (2000) p. 112</ref> the only U-boat sunk in the Gulf of Mexico during World War II<ref name=Boyle2015>{{cite news |author=Boyle, Alan |title=How an Expedition to Study a Sunken Nazi U-Boat Rescued a Reputation |date=6 May 2015 |publisher=NBC News |url=http://www.nbcnews.com/science/science-news/how-expedition-study-sunken-nazi-u-boat-rescued-reputation-n354826 |access-date=7 May 2015 }}</ref>
* {{GS|U-94|1940|2}}: sunk on 27 August 1942 by a [[Consolidated PBY Catalina|PBY-5A Catalina]] from [[VP-92]] and {{HMCS|Oakville}} in position {{coord|17.40|-74.30|display=inline|type:event}}.<ref>{{cite book |last1=Roberts |first1=Michael D. |title=The History of VP, VPB, VP(H) and VP(AM) Squadrons |series=Dictionary of American Naval Aviation Squadrons |volume=2 |date= 2000 |location=Washington D.C. |publisher=Naval Historical Center Department of the Navy |page=707}}</ref>
* {{GS|U-165|1941|2}}: sunk on 27 September 1942 by a [[Vickers Wellington]] of [[No. 311 Squadron RAF|311/Q Squadron]], RAF (with a Czech aircrew)
* {{GS|U-132|1941|2}}: sunk on 5 November 1942 by aircraft of [[No. 120 Squadron RAF]].
* {{GS|U-517||2}}: sunk 17 November 1942 by [[Fairey Albacore]]s of [[817 Naval Air Squadron]] from the aircraft carrier {{HMS|Victorious|R38|6}}.l
* {{GS|U-553||2}}: lost at sea 28 January 1943
* {{GS|U-69|1940|2}}: active in the east coast operations, rammed and sunk on 17 February 1943 by {{HMS|Fame|H78|6}}
* {{GS|U-106|1940|2}}: active in the east coast operations, sunk 2 August 1943, by aircraft attack by [[No. 461 Squadron RAAF]] flown by Flight Lieutenant A. F. Clarke.

==Notes==
{{Reflist}}

==Bibliography==
* Bauer, E. ''The History of the Second World War''.
* {{cite book |last=Behrens |first=C. B. A. |author-link=Betty Behrens |series=History of the Second World War: United Kingdom Civil Series |title=Merchant Shipping and the Demands of War  |year=1955 |publisher=HMSO and Longmans |location=London |oclc=557756251|url=https://archive.org/details/merchant-shipping-demands-of-war}}
* Blair, Clay ''Hitler's U-Boat War: The Hunters 1939–1942'' Random House (1996) {{ISBN|0394588398}}
* {{cite book |last=Churchill |first=Winston |author-link=Winston Churchill |title=The Hinge of Fate |series=[[The Second World War]] |publisher =Houghton Mifflin Company |date=1950 |location=Boston}}
* {{cite book |last=Cressman |first=R. J. |year=2000|title=The Official Chronology of the U.S. Navy in World War II |location=Annapolis |publisher=Naval Institute Press |isbn=1557501491 |url-access=registration|url=https://archive.org/details/TheOfficialChronologyOfTheUSNavyInWorldWarII}}
* Ellis, John. ''The World War II Databook: The Essential Facts and Figures for All the Combatants''. London: Aurum Press, 1993. {{ISBN|1854102540}}.
* Fairbank White, David. ''Bitter Ocean: The dramatic story of the Battle of the Atlantic 1939–1945'', 2006, Headline Publishing Group, {{ISBN|9780755310890}}.
* {{cite journal |last1=Fisher |first1=Robert C. |date=April 1993 |title='We'll Get Our Own': Canada And The Oil Shipping Crisis Of 1942 |url=https://www.cnrs-scrn.org/northern_mariner/vol03/tnm_3_2_33-39.pdf |journal=The Northern Mariner |volume=3 |issue=2 |pages=33–39 |publisher=Canadian Nautical Research Society; North American Society for Oceanic History |doi=10.25071/2561-5467.772 |s2cid=247653126 |access-date=23 January 2022}}
* Gannon, Michael. ''Operation Drumbeat: The Dramatic True Story of Germany's First U-Boat Attacks Along the American Coast in World War II''. New York: Harper & Row, 1990. {{ISBN|0060161558}}.
* {{cite book |last1=Milner |first1=Marc |authorlink=Marc Milner |year=2011 |title=Battle of the Atlantic |edition=2nd |location=Stroud |publisher=The History Press |isbn=978-0-7524-6646-0}}
* Morison, Samuel Eliot. ''A History of U.S. Naval Operations in World War II Vol. I: The Battle of the Atlantic, September 1939 – May 1943''. Boston: Little, Brown, 1947.
* {{cite book|last= Roskill |first= Stephen Wentworth |authorlink=Stephen Roskill |title=The War at Sea, 1939–1945 |volume=II The Period of Balance |series=[[History of the Second World War]] |location=London |publisher=HMSO |date= 1956}}
* Tennant, Alan J. ''British and Commonwealth Merchant Ship Losses to Axis Submarines 1939–1945'' Sutton (2001) {{ISBN|0750927607}}
* ''U-Boat War''. (2001). BFS Video. {{asin|B00005BGQZ}}. {{UPC|066805814440}}.

== External links ==
* {{cite web|url=http://uboat.net/fates/losses/1942.htm|title=List of U-boat sinkings|last=Helgason|first=Guðmundur|website=German U-boats of WWII – uboat.net}}
* [https://web.archive.org/web/20061022172850/http://www.rafcommands.com/Coastal/53C.html No 53 Squadron, Royal Air Force, list of bases]
* [http://www.rnpatrolservice.org.uk More information about RN Armed Trawlers and the Royal Naval Patrol Service in WW2]

{{Authority control}}
[[Category:1942 in Germany]]
[[Category:1942 in military history]]
[[Category:Battle of the Atlantic]]
[[Category:Naval battles of World War II involving Germany]]
[[Category:Naval battles of World War II involving the United States]]
[[Category:Naval battles of World War II involving Canada]]
[[Category:Karl Dönitz]]