The submarine has had many incarnations over the past few centuries. Its technology has seen enormous innovation and has been extremely revolutionary since its conception during the Renaissance era. Although it was initially developed as a simple method of underwater exploration, over time it transformed into one of the most powerful weapons of war ever created. The concept of underwater technology had humble beginnings with the use of simple diving bells, but over the coming centuries we will see the development of a range of different submarines, from basic craft to wood to today's nuclear fleets. The diving bell could be considered one of the most primitive submarines. types of technology in the vein of the submarine. The diving bell was an enclosed structure that retained air when submerged underwater, allowing people to enter and submerge as well. One of the first accounts of this technology was described by Aristotle in the 4th century BC. About diving bells he writes: "They allow divers to breathe equally well by dropping a cauldron, because this does not fill with water, but retains air, because it is pushed directly into the 'water. » <1> While The idea of ​​the diving bell was conceived over two thousand years ago. It was not until the Renaissance era that more sophisticated plans for underwater ships began to develop. Throughout this era, many physicists and inventors such as Guido da Vigevano and Roberto Valturio drafted plans for. underwater technology. However, these plans never came to fruition. It was not until 1578 that detailed plans were drawn up to produce a vehicle capable of navigating underwater. Englishman William Bourne designed a prototype for what we would today call a submarine and published the designs in. his book Inventions Or Devi...... middle of paper ......ar engines However, there continue to be constant innovations in the speed and endurance of today's watercraft. For example, the Russian Typhoon class submarines are the most efficient. The largest ever seen, measuring 175 meters long, it can remain submerged for three months.<22> The military interest aroused by the submarine since the end of the 19th century quickly caused the invention to evolve into its modern form . Nowadays, small modern submarines are also used for civilian purposes. For example, many scientists would use small two- or three-man boats to go on underwater explorations. Submarines are now even used for entertainment purposes by resorts and other similar companies to take tourists on underwater excursions. Underwater technology is now available to everyone in a variety of ways, but it also continues to be innovated with new improvements in the power of these vessels made every year..