That's pretty damn cool, leo. I've done a couple night dives and I've never seen anything remotely as incredible as that. How deep were you? And what kind of camera/housing were you using?
It's actually pretty shallow. We are literally sitting at 35 feet. I'm actually laying on my stomach, but you can see lots of people sitting. As for the camera, I haven't graduated to those really big and REALLY expensive underwater rigs ($10k+). I use a Canon powershot SD940is and the associated underwater case that Canon makes for it. The setup works remarkably well for clear water conditions like Hawaii. Our home dive is Monterey and it's not as good there because the visibility is much worse. For this Manta dive, the ambient light from all the other divers (there's also lots of snorkelers on the surface), works really well to illuminate the scene.
There's some other videos on my Youtube channel of Spinner Dolphins we saw and some White Tip Reef Sharks that we were lucky enough to come by during a day dive, as well as more from the Manta dive. Please check them out, too!