[Sangetsu]

Commercial diving is a profession, but finding a position in Japan would be difficult. Most dive work is done for oil companies or ship builders. Japan has no oil industry, though it does have a rather large ship building industry. Unfortunately, these ships are maintained and repaired in-house, and generally Japanese are hired for what positions there are. And you can't forget that the US Navy has a strong presence in Japan, and their divers usually get the first pick of whatever work is available.

Your best option is to get a job with one of the larger oil companies. Ocean exploration is being ramped up at the moment, and it won't be long before offshore drilling begins in America. You should be taking your course as soon as possible.

One of the better companies to work for as a diver would probably be Schlumberger (shlom ber jay).