ScubaDoo
From the website:
Scubadooing means you don’t need to wear a mask or a mouthpiece as in diving, the external compressor is floating above water, and the diving weights are on the ScubaDoo, not you!
You are seated on your ScubaDoo, with your head and shoulders within a clear dome, your air constantly replenished from the external compressor, enabling you to breathe normally!
Maneuverable? You bet! At a rate of 2.5 knots you’re able to ride amongst the spectacular underwater world, or remain stationary while you feed the fish.