Although most of the advances in underwater exploration have taken part in the last 400 to 500 years, it is important to note that the Vikings showed considerable interest in uncovering what lies beneath the sea. In the 700s they used sounding weights to obtain and collate samples of the sea bed as well as to calculate the depth of the sea. This was an important building block on which the continuation of this kind of exploration depended on.
Fast forward to 17th century and the first submarine is built by Cornelius Drebbel. The test drive took place in the Thames in 1620; it was made from wood and animal skin. This shows that even before industrialisation humans were curious about what lies beneath our oceans and interested in reaching the seabed. Just a century later and the French scientist Pierre-Simon Laplace was building on the work of the Vikings by estimating the depth of the Atlantic Ocean. This was later proved to be very accurate.

The 18th century also saw the invention of a diving suit by Karl Klingert that was airtight and contained a metal tube. This showed the advancement of the science behind exploration – the 18th century acted as a catalyst for the development of underwater exploration as afterwards there was an explosion of many different submarine missions. France built the first human-powered submarine in 1800 and in the 1860s, the US Navy showed an interest in building submarines. By the end of the 19th century the first modern electric submarine called the Gymnote had been created in France.

Submarine technology was constantly advancing – however, technology for the divers themselves only really advanced in 1943 with Jacques Cousteau and Emile Gagnan. They invented the aqua-lung which could regulate air according to what the diver required meaning divers could now easily breathe underwater. This was a huge advancement as it was now a lot safer for humans to explore oceans. Again, this was created by the French, showing the massive impact the French had on the development of underwater technology.

Since then submarines have been developed further – the wreckage of the Titanic has been found and the Census of Marine Life has been completed. Without Cousteau, Drebbel, and many other inventors,this would not have been possible. We would not have been able to explore the ocean as in depth, if at all, without their creations and findings.