Powered Dive Helmet (BOB)

This is the BOB diving vehicle (Breathing Observation Bubble) which is built as a way for chaperoned non-divers to experience the underwater world.  My impression is that it's a powered, full-body SCUBA helmet.  I mean that in a good way though - I'd like to try it. 

The link above has some technical stats: 2.5kt top speed from the 12V electrical drive, 58lbs weight, and a 40ft max depth. 

These have been around for awhile, built I think by the Bellaqua Personal Submersibles company which seems to be defunct.  I don't know how many BOBs were built but the first website listed here runs trips from Sand Key, Florida which is near Key Largo and down in the Florida Keys.

  http://www.sfdj.com/bob/bob.htm

Or if you're in Cancun:

  http://www.cancunbob.com/

the Virgin Islands:

  http://www.bobusvi.com/

or Ajaccio, France (on Corsica):

  http://www.bob-diving-center.com/index.htm