This is a video shot at the 2009 annual get-together of the Personal Submersibles Organization, which groups folks who build personal submarines as a hobby.
Normally members bring home-built submersibles to the event, but this year was an exception. The meeting was hosted by Phil Nuytten, probably the world's best known builder of commercial grade subs. With characteristic generosity, Phil allowed all convention attendees to dive his boats. So in this year's video, the pilots are amateurs but the subs are very professional indeed. Please check other videos tagged with "PSUBS" to see the home-built subs in action, or if looking for more information on this hobby visit WWW.PSUBS.ORG.