Unfortunately no one on the dive got a picture so I'll try to describe as best I can.

Saw a blueish-purple creature at 102' (31m) at Saba's pinnacles (90' / 27m at top, 200' / 60m plus at bottom) in the Caribbean. At first I thought it was a strange-colored sponge in a crevice, and on further investigation saw that it was moving, slowly. It was tubular, maybe 1.5" diameter, moving from one crevice to another so never saw the whole thing at once. I may have seen a head, but can't really be sure. It moved almost like a sea cucumber, oozing down from the higher crevice. For lack of a better description (sorry for the weak-stomached!) it looked like small intestines moving over the reef, but definitely blueish. We made sure to shine a light on it to counteract any underwater illusions. No markings on the skin, smooth texture, no dimples, not segmented, just some light transverse striations, again like some sea cucumbers. But I swear it was blueish purple...

Two Divemasters and three seasoned divers - all with a couple thousand Caribbean dives each! - had no clue what it was... Has anyone seen anything like this before?

Thanks for any help you might be able to provide! I'm insanely curious about this thing...

Kat