Recently, I bought underwater housing for my video camera and I think shooting photo for many years has provided me with a "good head start" on filming in the ocean environment.  You'll also find a few short clips on this site which I think you'll really enjoy.  Especially, one of the Manta in Kona swimming right into the camera - a thousand pounds of Manta running into you a night is pretty exhilarating!!!

Manta Ray Night Dive - Kona, Hawaii: "A One on One Encounter" - please click on the photo to view our video.