A few Russian subs. Check-out the features involved with construction and assembly-the Borei class sub. Notice that there are a few more hits on the right of the screen-what the Russian's claim to be the largest sub-interestingly, several other countries make the same claim, including France and Japan. Possibly, (according to lobster divers) there is a small 2 man Japanese sub sunk off shore here in about 500 feet of water-early sightseers would suspect?

http://www.youtube.com/watch?v=ukv1bwn619M&NR=1