So whenever you see a 4 foot tail sticking out from under a rock, you really have to get down under the rock too to find out what's down there. This wasn't really a surprise.
The tail here belongs to the green moray below. Green morays are our biggest morays and, to my surprise, I think this may be the first one to appear on E,W&W. I see them far less frequently than the spotted or goldentail morays and they get a lot bigger.
This eel is currently occupying a place in green moray legend. It is resident on the wreck of RMS Rhone. In the film The Deep a monstrously big green moray menaces various people apparently so, as the current incumbent on the wreck, this guy has a job to live up to any number of tourists' expectations. It moves around the wreck a lot which is unhelpful when trying to find it but it turns up fairly regularly. If you are wondering what the stripey thing near its left eye is we'll be getting to that shortly.