This is a critter I had never seen before, for good reason: the hole that it is peeking out of is smaller than the tip of your little finger. Two of the three dive masters were experts in finding things even I could barely see....
I had to crop this more than I would like. With the 60mm lens, if I got close enough to make the crab fill the frame more, there was no way to get light into the hole to illuminate the little guy. But a very cute critter, worth the effort.