• Pytheas of Massalia (c. 325 BC)
  • Greek explorer known for his voyage to the north, possibly reaching Britain and exploring the Arctic Circle.

• Hanno the Navigator (5th century BC)
  • Carthaginian explorer who led a fleet along the West African coast, possibly reaching as far as modern-day Guinea.

• Eratosthenes (c. 276–194 BC)
  • Though more a scholar, he calculated the Earth's circumference with remarkable accuracy, contributing to navigation science.

• Nearchus (4th century BC)
  • Greek admiral under Alexander the Great, known for his voyage from the Indus River back to Susa along the Persian Gulf.

• Himilco the Navigator (5th century BC)
  • Carthaginian who explored the Atlantic coast of Europe.

• Zheng He (1371–1433)
  • Chinese admiral and explorer who led seven major voyages across Southeast Asia, the Indian Ocean, and possibly as far as East Africa during the Ming Dynasty.

• Prince Henry the Navigator (1394–1460)
  • Portuguese prince who funded and directed explorations along the West African coast, significantly advancing European knowledge of the Atlantic.

• Bartolomeu Dias (c. 1450–1500)
  • Portuguese explorer who was the first to sail around the southern tip of Africa, reaching the Indian Ocean.

• Christopher Columbus (1451–1506)
  • His voyages across the Atlantic led to European awareness of the Americas, although he thought he had reached Asia.

• Vasco da Gama (c. 1460s–1524)
  • Portuguese explorer who was the first to reach India by sea, linking Europe and Asia via the Cape of Good Hope.

• John Cabot (c. 1450–c. 1499)
  • Italian explorer who explored the coast of North America for England.

• Amerigo Vespucci (1454–1512)
  • Italian explorer whose voyages confirmed that South America was not Asia but a new continent, which was later named after him.

• Ferdinand Magellan (1480–1521)
  • Portuguese (in Spanish service) whose expedition was the first to circumnavigate the globe, although he was killed during the journey.

• Juan Sebastian Elcano (c. 1476–1526)
  • Completed Magellan's expedition, becoming the first to circumnavigate the Earth.

• Jacques Cartier (1491–1557)
  • French explorer who claimed what is now Canada for France.

• Sir Francis Drake (c. 1540–1596)
  • English sea captain who completed the second circumnavigation of the world.

• Henry Hudson (c. 1565–1611)
  • English navigator who explored parts of North America, including the Hudson River and Hudson Bay.

• James Cook (1728–1779)
  • British explorer known for his three voyages of discovery in the Pacific Ocean, mapping New Zealand, Australia, and the Hawaiian Islands.

• Matthew Fontaine Maury (1806–1873)
  • American oceanographer and naval officer, known as “Pathfinder of the Seas” for his work on ocean currents and wind patterns, which greatly aided navigation.

• Roald Amundsen (1872–1928)
  • Norwegian explorer who led the first expedition to reach the South Pole and the first to navigate the Northwest Passage.

• Prince Henry the Navigator (1394–1460)
  • Portuguese prince who sponsored numerous voyages along the West African coast, advancing maritime navigation.

• Bartolomeu Dias (c. 1450–1500)
  • Portuguese explorer who first rounded the Cape of Good Hope, opening the sea route to Asia.

• Christopher Columbus (1451–1506)
  • His voyages across the Atlantic introduced Europeans to the Americas, although he believed he had reached Asia.

• Vasco da Gama (c. 1460s–1524)
  • Portuguese explorer who completed the first sea voyage from Europe to India via the Cape of Good Hope.

• Amerigo Vespucci (1454–1512)
  • Italian explorer whose voyages confirmed that the lands Columbus reached were a new continent, later named America.

• Ferdinand Magellan (1480–1521)
  • His expedition was the first to circumnavigate the globe, although he died in the Philippines.

• Juan Sebastian Elcano (c. 1476–1526)
  • Completed Magellan's expedition, thus completing the first circumnavigation.

• Jacques Cartier (1491–1557)
  • French explorer who explored the Gulf of Saint Lawrence and claimed Canada for France.

• Sir Francis Drake (c. 1540–1596)
  • English explorer who completed the second circumnavigation of the world.

• Henry Hudson (c. 1565–1611)
  • English navigator who explored parts of North America, including the Hudson River and Hudson Bay.

• James Cook (1728–1779)
  • British explorer whose voyages in the Pacific mapped numerous areas, including New Zealand, Australia, and the Hawaiian Islands.

• Matthew Fontaine Maury (1806–1873)
  • Known as the “Father of Oceanography”, he produced the first extensive oceanographic studies and wind and current charts.

• Charles Darwin (1809–1882)
  • While known for evolution, his observations during the voyage of HMS Beagle contributed to marine biology and geology.

• John Murray (1841–1914)
  • Scottish-Canadian marine biologist who was central to the Challenger Expedition, considered the foundation of modern oceanography.

• Fridtjof Nansen (1861–1930)
  • Norwegian explorer whose drift in the ice with the Fram provided insights into Arctic Ocean currents and marine biology.

• Roald Amundsen (1872–1928)
  • Explored polar regions, including the first successful navigation of the Northwest Passage and the South Pole.

• William Beebe (1877–1962)
  • American naturalist who conducted pioneering deep-sea dives using a bathysphere, exploring ocean depths previously unseen by humans.

• Jacques Cousteau (1910–1997)
  • French naval officer, explorer, conservationist, filmmaker, and inventor. Co-invented the Aqua-Lung, popularized marine life through documentaries like “The Undersea World of Jacques Cousteau,” and significantly advanced marine conservation.

• Sylvia Earle (1935 - present)
  • American marine biologist, explorer, author, and lecturer known for her deep-sea dives, marine biology research, and advocacy for ocean protection.

• Robert Ballard (1942 - present)
  • American oceanographer who discovered the wreck of the Titanic and numerous other shipwrecks, advancing deep-sea exploration technology.

• Don Walsh (1931 - present)
  • Along with Jacques Piccard, he was one of the two men to descend to the Challenger Deep, the deepest known point in the Earth's seabed.

• Jean-Michel Cousteau (1938 - present)
  • Son of Jacques Cousteau, he continues his father's legacy in marine exploration, education, and conservation through the Ocean Futures Society.

This list is not exhaustive but highlights key figures who have made significant contributions to our understanding of the oceans, navigation, and marine science.