From 1872 to 1876 the HMS Challenger explored all of the world’s oceans, with the exception of the Arctic. The Challenger Expedition is considered the turning point for modern oceanography because it was a large-scale, government-funded project with the sole purpose of ocean research and discovery. People were actually exploring the ocean long before Challenger’s crew, but not necessarily in the name of science. Most had other motivations from finding other lands for colonization to establishing trade routes. Oceans were not seen as something needing to be explored and were more of an obstacle to reach other goals. There was very little interest specifically in the oceans themselves.
As far back as 4500 BC people living in the coastal regions of Greece and China had were diving into the ocean as a means of gathering food. Later in 600 BC, the Egyptians are believed to have built the first ships for sailing, although they did not do any extensive exploration and likely kept to the Mediterranean for trade purposes with other ancient nations. The Greeks known for their love of science and studiousness were interested in studying the ocean. The philosopher Aristotle mentioned the use of a crude diving bell in his writings from 360 BC, indicating that there was a desire for underwater diving. Pytheas, another Greek scholar, astronomer, and geographer, sailed north out of the Mediterranean Sea in 325 BC. He used the north star to determine the latitude and he sailed to the coast of England, maybe even reaching Iceland and Norway. Pytheas was the first person to observe that tides were related to the moon’s phases, although it was not what he set out to do. In 150 BC, Ptolemy created his famous map of the known world, which included Europe, Asia, Africa and the surrounding oceans. The map was unfortunately lost until 1410.
In later centuries the main motivation for traveling the oceans was conquest. The Vikings sought to colonize other lands, not explore the ocean, but they ended up exploring the ocean no less around 900 AD. They were excellent seafarers, colonizing Iceland, Greenland, and Newfoundland while the other Europeans were in the Dark Ages. During that time, most people were terrified of the ocean because “there be monsters,” as was indicated on maps of the seas from that time period, featuring beasts in the oceans. Not much science at all went on for several centuries, much less oceanography. Ptolemy’s map was rediscovered in 1410 during the Crusades in an Arab-occupied Roman library, initiating a new interest in exploration again and opening up a new world.
The 1400s were filled with ship building and sailing, mainly to seek out new lands and establish trade routes. In 1492, Christopher Columbus sailed across the Atlantic trying to get to India, accidentally discovering North and South America. Vasco de Gama sailed around the Cape of Good Hope, South Africa in 1498 seeking to establish a path to India not as treacherous as traveling over land. The first circumnavigation of the world occurred in 1519 with Ferdinand Magellan from Portugal. The first actual diving bell was invented in 1535 by Guglielmo de Lorena. It allowed enough air for an approximately one-hour dive, again showing renewed interest in what went on below the water. Then in 1578, William Bourne drew up plans for the first submarine for underwater travel. It was a very crude design with a wooden frame covered with leather that would be rowed from the inside. It was never built.
Still no one was very interested in studying the oceans, but the tides would soon turn. The main motivation for submarines even was simply an alternative to above-water transport. The first actual submarine would be built in 1620. The Dutchman, Cornelius Drebbel constructed an underwater boat made of wood, reinforced with iron and covered in leather. It featured twelve oarsmen inside with the oars sticking out of tight leather holes. Drebbel made several trips in his submarine in the Thames River, reaching depths of twelve to fifteen feet. 1690 saw the first air-replenishing diving bell created by Edmund Halley. In 1698, Halley made the first scientific ocean voyage. His purpose was to study magnetic compasses though, not the ocean. While on this journey he observed the trade winds and ocean currents as well. In 1768, the English ship Endeavor was sent to observe the path of the planet Venus and during that time, Lieutenant James Cook mapped the Pacific Ocean. Several decades later in 1785, Benjamin Franklin sent a letter about the Gulf Stream to a colleague in France. The letter, known as the Sundry Maritime Observations, in addition to the discovery of the Gulf Stream also addressed ship propulsion, hull designs, and some sea disasters.
The seventeenth century saw a great deal of progress in oceanography and genuine interest in the ocean itself. In 1807, President Thomas Jefferson creating the US Coast Survey. The organization worked to record data about tides, currents, the seafloor, and depth of the Atlantic Ocean off of the eastern coast. The first use of scuba equipment (which stands for self-contained, underwater, breathing apparatus) was by Englishman William H. James in 1825. The diver wore a helmet and had a supply of compressed air, but like the previous devices the diver could only stay underwater for around an hour. Charles Darwin, doing his groundbreaking work on the theory of evolution on the HMS Beagle, also proposed that the ocean may contain ancient creatures in 1831. In 1837, more improvements were made on the diving suit by Augustus Siebe, a German instrument maker. The suit he created would be used for over a century. It allowed more mobility than the previous suit. At the beginning of 1840, sounding was invented. Sir James Clark Ross conducted the first measurements of ocean depth using sounding. Darwin published his observations on coral reefs in 1842 and a year later in 1843, the British naturalist Edward Forbes proposed that there was no life in the ocean below 1,800 feet, which prompted a twenty year debate and one of the goals of the Challenger Expedition was to disprove that theory.