Anyone that has seen a special on the Discovery Channel has probably felt a pull toward taking his or her own dive. Since the YMCA offered the first diving courses in 1959, one needn't be an expert or Navy Seal to take the plunge.

The military has long been fascinated with stealth methods of maneuvering around one's enemy, so naturally scuba diving took off. During the Trojan Wars, divers sabotaged enemy vessels by boring holes in the ships' hulls. The Greeks also tried constructing elaborate underwater defensive shields to keep their attackers away.

In 500 BC, Scyllias, a Greek soldier, dove from Persian King Xerxes' ship and held his breath underwater for hours, using a hollow reed as a snorkel, until he could alert his compatriots of the imminent danger.

In 414 BC, Thucydides wrote of divers who swam to the bottom of the ocean to remove underwater obstacles so their ships could pass safely into the harbors.

In 332 BC, Aristotle reported that Alexander The Great was lowered into the water in "a fine barrel made of white glass" -- which was made out of a bell -- during the siege of Tyre. The Italians used scuba gear extensively in WWII and American combat divers were dubbed "frogmen" for their initially shocking appearance.

Scuba diving was not just used for protection, but also for sustenance. In 1000 BC, Homer wrote in his book, The Odyssey, about how fishermen dove 100 feet, using a rock to expedite their submersion, to collect sponges.

Divers would pour oil into their ears and mouths before diving to reduce pressure and used a tether to reach the surface once they had cut as many sponges as they could. By 100 BC, the profit potential of Mediterranean deep sea excavation was realized.

Inventors were fascinated with the idea of scuba diving and creating scuba gear to allow individuals to remain underwater for hours at a time. While Leonardo da Vinci dreamt up some of the first prototypes and patents were issued for "rebirthing" devices in the 1700s, Jacques Cousteau was credited with the first successful functioning design in the 1940s.

A book written by Cousteau in the 1950s is said to have created a recreational scuba diving industry, drawing thousands of fearless divers - despite obvious dangers. In the next decade, YMCA and the Professional Association of Diving Instructors offered diving courses to the average person to decrease the number of diving-related accidents.

There's a lot to be excited about in the scuba diving world world these days. In August 2007 alone, divers were excavating Blackbeard's pirate ship off the North Carolina coast, a WWII submarine (the USS Grunion) off the Alaskan coast and ships from the Byzantine Empire in the Black Sea. For the true adventurer, it is the ocean -- and not space -- that has become the final frontier for mankind.