I run a marine education field station on a small caye off the coast of Belize, and was leading a group snorkel in very unfavourable conditions when I spotted this guy on the rubble. The water temperature was between 70 and 75F, which was very low for this area - we were going through a cold front and had been for several days - and the water was very choppy with loads of sargassum floating around, and the visibility was less than 10ft. As I said, very unusual for us. I could only get a few (bad) photos of this eel(?) as I had to keep our group moving, but he was about a foot long and was being surged around on the coral rubble in water about 4ft deep.
Any help would be appreciated!