Supermarine Sea Otter

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

Sea Otter
A prototype Supermarine Sea Otter.jpg
Prototype of Sea Otter
Role Amphibian
Manufacturer Supermarine
First flight 23 September 1938
Primary users Royal Air Force
Royal Navy
Royal Danish Air Force
Produced 1942–1945
Number built 292
Developed from Supermarine Walrus

The Supermarine Sea Otter was a British amphibious aircraft designed and built by Supermarine; it was a longer-range development of the Walrus and was the last biplane flying boat to be designed by Supermarine; it was also the last biplane to enter service with the Royal Navy and the RAF.

Design and development[edit]

The main difference between the Walrus and the Sea Otter was in the mounting of the powerplant; the Walrus had a rear-facing engine with a pusher propeller and the Sea Otter's engine faced forward with a tractor propeller.

Sea Otter I of the Marine Aircraft Experimental Establishment in 1948

There was considerable development of the power plant/propeller combination during the design of the Sea Otter, which at its conception was called the "Stingray". The original test aircraft had a Bristol Perseus XI radial engine with a two-bladed propeller, which gave insufficient thrust so a two-position three-blade propeller was substituted, later changed again to a four-bladed type with the pairs of blades set at an angle of 35°, instead of the usual 90°. The first flight took place on 23 September 1938, but it was not until January 1942 that the Air Ministry placed a production order. Due to cooling troubles found with the Perseus, the power-plant was changed for production aircraft to the Bristol Mercury XXX engine driving a three-bladed propeller. The Sea Otter was used by both the RAF and the Royal Navy for air-sea rescue and patrol roles.

Postwar, Sea Otters were converted for civilian use. The cabin was soundproofed and fitted with heating. Seating for four passengers, a chemical toilet and a stowage for baggage were provided. As they were intended for use as Bush airplanes in remote areas, versatility was important. To allow cargo to be carried, the cabin floor was strengthened and fitted with lashing points, and the passenger seats made easily removable.[1]


Of the 592 aircraft ordered, only 292 were built due to the end of the Second World War. Eight aircraft were bought for the Royal Danish Air Force, and another eight were supplied to the Dutch Naval Air Arm. The colonial service of France purchased six Sea Otters for use in French Indochina.


Sea Otter Mk I
Reconnaissance and communications amphibian aircraft.
Sea Otter Mk II
Air Sea Rescue amphibian aircraft.


 United Kingdom

Specifications (Sea Otter)[edit]

Data from Supermarine Aircraft since 1914[4]

General characteristics

  • Crew: Four
  • Length: 39 ft 10¾ in (12.16 m)
  • Wingspan: 46 ft 0 in (14.02 m)
  • Height: 15 ft 1½ in (4.61 m)
  • Wing area: 610 ft² (56.7 m²)
  • Empty weight: 6,805 lb (3,093 kg)
  • Loaded weight: 10,000 lb (4,545 kg)
  • Powerplant: 1 × Bristol Mercury XXX radial piston engine, 965 hp (720 kW)




No museum holds a complete aircraft. The Fleet Air Arm Museum (Australia) at Nowra, New South Wales, Australia, has the nose section of JN200, a Sea Otter which served with the Royal Australian Navy.[5]

See also[edit]

Related development

Aircraft of comparable role, configuration and era

Related lists


  1. ^ "Civil Sea Otter". Flight: 383–384. 10 October 1946.
  2. ^ a b c d e f Halley 1980, p. 354.
  3. ^ Sturtivant and Ballance 1994, p.363.
  4. ^ Andrews and Morgan 1987, p. 162.
  5. ^ Lambert, Roger. "RAN Sea Otter Dataplate" (PDF). Retrieved 16 May 2013.


  • Andrews, C.F. Supermarine Aircraft Since 1914. London: Putnam, 1981. ISBN 0-370-10018-2.
  • Andrews, C.F. Supermarine Aircraft Since 1914. London: Putnam, Second edition, 1987. ISBN 0-85177-800-3.
  • Halley, James J. The Squadrons of the Royal Air Force. Tonbridge, Kent, UK: Air Britain (Historians) Ltd., 1980. ISBN 0-85130-083-9.
  • Sturtivant, Ray and Theo Ballance. The Squadrons of the Fleet Air Arm. Tonbridge, Kent, UK: Air Britain (Historians) Ltd., 1994. ISBN 0-85130-223-8.

External links[edit]

Media related to Supermarine Sea Otter at Wikimedia Commons