" (qtd. Earle 25). Obviously the unknown fills us with curiosity, such as in my case, and it pushes us to develop other methods of venturing below our limitations. .
As curiosity grew so did technology to dive deeper into the unknown. Scuba Diving was the next stepping stone for marine exploration, specifically, the scuba. The self-contained underwater breathing apparatus (scuba) was invented and allowed divers to breath in air from their tanks at the same pressure as that of the surrounding water (Day 220). This along with a diving suit, a mask, and fins allowed divers to descend to a depth of 1,970 feet, a radical improvement from holding ones breath. I found it fascinating that a symptom of approaching the depth of 200 feet was nitrogen narcosis, very similar to drunkenness. Another interesting piece of information I found was the world's only underwater laboratory, Aquarius-2000, is owned by the United States and provides scuba divers with a productive research facility (Day 221). Although scuba diving was a far-reaching improvement it could only take divers so far under the water's surface. I believe people's curiosity was only met for a short time and if they wanted to fulfill it completely they would have to go to the bottom of the ocean.
To go beyond the depth of 1,970 feet, the diver needed to be protected from the high pressure by being surrounded in a vessel or shell of some kind. A large underwater metal craftof course I am talking about submarines. Today, there are two kinds of submarines: the conventional and the nuclear-powered. The conventional are powered by diesel engines when near the surface and use battery power when underwater (Day 221). I never knew submarines could run on diesel engines, I always thought they were powered by gasoline same as most cars and planes. Also conventional submarines need to surface to recharge their batteries and vent waste gases, so these submarines are more restricted than other submarines (Day 221).
