Ocean exploration is a part of oceanography describing more generally the exploration of ocean surfaces. It is also the period when people explored the ocean boundaries. Notable include: the Greeks, the Egyptians, the Polynesians, the Phoenicians, Phytheas, Herodotus, the Vikings, and the Portuguese. Travel on the surface of the ocean through the use of boats dates back to prehistoric times, but only in modern times has extensive underwater exploration become possible. Scientific investigations began with such early scientists as James Cook, Charles Darwin and Edmund Halley. Ocean exploration itself coincided with the developments in shipbuilding, diving, navigation, depth measurement, exploration and cartography.
Timeline of Ocean Exploration 
Early exploration 
- 130,000 BCE Researchers working on the island of Crete discover stone tools indicating ocean exploration capabilities of pre-human ancestors dating to at least 130,000 years ago 
- 4500 BCE Around this time, cultures like those in Greece and China began diving into the sea as a source of food gathering, commerce, and possibly even warfare.
- 4000 BCE Egyptians developed sailing vessels, which were probably used only in the eastern Mediterranean near the mouth of the Nile River.
- 4000 BCE - 1000 AD Polynesian colonization of South Pacific Islands.
- 1800 BCE Basic measuring of the depths is done in Egypt.
- 1500 BCE Middle Eastern peoples explored the Indian Ocean
- 600 BCE Phoenicians developed sea routes around the entire Mediterranean and into the Red Sea and the Indian Ocean. Going around Africa they reached England by sailing along the western European coast. Although they understood celestial navigation, they probably stayed within sight of land whenever possible.
- 500-200 BCE Greeks developed trade routes in the Mediterranean using the length of the day (corrected for the time of the year) to estimate latitude.
- 450 BCE Herodotus publishes a map of the Mediterranean region.
- 325 BCE Pytheas, a Greek astronomer and geographer, sailed north out of the Mediterranean, reaching England and possibly even Iceland and Norway. He also developed the use of sightings on the North Star to determine latitude.
- c.240 BCE Eratosthenes of Alexandria, Egypt determines fairly accurately the circumference of the Earth using angles of shadows in Syene and Alexandria.
- 150 BCE Ptolemy produces a map of the Roman world, including lines of latitude and longitude, the continents of Asia, Europe, and Africa and the surrounding oceans.
- 900-1430 Vikings explore and colonize Iceland, Greenland, Newfoundland.
- 1002 CE Leif Erikson reaches North America 500 years before Columbus.
- 1405-1433 Chinese send seven voyages to extend Chinese influence and impress their neighbor states. These expensive voyages are ended after a short time. See Zheng He (1371–1433).
From Age of Exploration to present 
- 1492-1504 Christopher Columbus reaches America looking for a searoute to the Indies; discovering various lands and islands and establishing a colony on Hispaniola
- 1498 Vasco da Gama sails around Africa from Portugal reaching India and establishing trade routes
- 1499-1504 Amerigo Vespucci explores New World
- 1519-1522 Ferdinand Magellan's ships circumnavigate the world.
- 1620 Dutch physician Cornelis Drebbel builds the world's first submarine and makes several trips in the River Thames near London at a depth of about 12 or 15 feet.
- 1698-1700 Edmund Halley made probably the first primarily scientific voyage to study the variation of the magnetic compass, sailing as far as 52 deg S. in the Atlantic Ocean. On a previous expedition to St. Helena, he made an important contribution to knowledge of the trade winds.
- 1768-1780 James Cook explores the southern parts of the oceans looking for the southern continent. He was the first to use a marine chronometer to determine longitude.
- 1785 Benjamin Franklin writes Sundry Marine Observations on improvements to ships and the Gulf Stream.
- 1831-1836 Charles Darwin sails on the Beagle, exploring the Galapagos and many other areas. It is this work which led him to develop the concepts of natural selection and evolution.
- 1860 First chart of the Gulf Stream published by the U.S. Coast Survey.
- 1872-1876 The H.M.S. Challenger travels around the world on a scientific mission; taking sediment samples, water samples, soundings, and collecting many biological specimens.
- 1960 Bathyscaphe Trieste dives to what was believed to be the deepest point in the Mariana Trench. A depth of 10,915 meters was observed.
See also 
- Deep-sea exploration
- Office of Ocean Exploration
- List of explorers
- List of maritime explorers
- Strasser, Thomas F.; Eleni Pangopoulou, Curtis N. Runnels, Priscilla M. Murray, Nicholas Thompson, Panayiotis Karkanas, Floyd W. McCoy and Karl W. Wegman. (April-June 2010). "Stone Age Seafaring in the Mediterranean: Evidence from the Plakias Region for Lower Paleolithic and Mesolithic Habitation of Crete". Hesperia: The Journal of the American School of Classical Studies at Athens 79 (2): 145–190.
- Sverdrup, Keith A.; Alyn C. Duxbury and Alison B. Duxbury (2005). An Introduction to the World's Oceans. New York: McGraw-Hill. p. 4. ISBN 0-07-252807-9.
- NOAA, Interactive Timeline of significant and interesting events throughout the 200-year history of NOAA and its predecessor organizations.
- SeaSky.org - Ocean Exploration Timeline with Credits & Sources
- NOAA - Sounding Pole to Sea Beam
- History of Ocean Exploration
- USC Earth Sciences, History of Oceanography
- skb's virtual cave - Notable oceanographic expeditions
- Ocean Explorer - Public outreach site for explorations sponsored by the Office of Ocean Exploration.
- NOAA, Ocean Explorer History
- NOAA, Ocean Explorer Gallery - A rich collection of images, video, audio and podcast.
- NOAA's Office of Ocean Exploration
- Deep-sea exploration