Came down on top of the boilers. There had been a lengthy debate on the surface about how to handle the current because we were diving several hours off slack water. We needn't have wasted our breath - there was no current. Swam round a completely different part of this enormous wreck than that which I had dived at Easter. Saw a huge fish which seemed fascinated by us. Zoe tried to signal something about the fish which I didn't understand so I handed her my slate. She wrote 'It's following us'. In retrospect I think the fish was actually trying to defend its territory because it was making threatening gestures - a bit like those photographs you see of a fish menacing its own reflection in a mirror. Couldn't find the shot line, got quite cold after a while so we surfaced using a delayed SMB.