Drawn from this sketch. The shafts of underwater light were heaps of fun to experiment with. The same elements were used to make the Sea Steve banner image.
I don't know if I'm 100% happy with this one yet (the starfish and crab look great when rendered big, but they're a bit hard to make out, and the sand could maybe do with some work), but I'll call it finished for the moment.
*FYI: There's a short but somewhat uninteresting story about why we call stingrays 'Steves' and you can read it here, if that's what you're into.