dude, fat floats

that's not gonna be good if he has gills

If fat floats, then why do dead whales sink? =P That and the beast has nostrils in the pic.

Last I knew, it was the air in the lungs that helps keep whales and other marine mammals afloat. And by the looks of this, the sea dragon breathes air. The fat (or blubber), is mainly there to keep the animal warm in the colder ocean waters. So technically this makes sense in a scientific fashion, especially if the dragon lives in the northern regions where it gets cold. Have you ever REALLY looked at a walrus? Those things are huge, yet they can still swim effectively and dive to the bottom.