This is a "wet" submarine. It doesn't try to keep water out. You wear SCUBA gear while pedaling it. And yes, it is powered by a person pushing pedals. That motion, through a drive train, makes manta-style wings flap. This explains the name, since rays are
Batoids, and this sub is a fake Batoid, not a real one. It's a beautiful piece of work, and Martin Plazyk is obviously proud to show it off. He and his father, Bruce, operate as
Faux Fish Technologies. Follow that link and you'll see many photos, along with a nice selection of videos showing their creations not just in static above-water displays, but in their natural (underwater) element. Meanwhile, here on Slashdot, Martin tells how Faux Fish subs are made. (
Alternate Video Link)