I went down on the wreck of the Battleship Hood with my old instructor Tom Reid. Tom told me about a cage of fish he wanted to show me. We raced down the shot line and to the south side of the wreck before finning up and against quite a strong current to get the north side. This was rather a deep dive for me and it was pretty dark with poor vis. We got to an opening in the side of the wreck and Tom signalled to me that he wanted to penetrate the wreck just a little bit (he held his thumb and forefinger about a centimetre apart). I thought he had gone bananas and went in what I considered 'just a little bit' i.e. about a metre. Tom went in much further and signalled that I should follow. I plain refused and couldn't understand what had got into him. It turned out that a bit further on was the cage of fish he had been telling me about. I apologised for not following him, but he said that I had been quite right not to go in and that he should have explained before the dive that the cage of fish was actually a little bit inside the wreck. Lesson learned: it is quite right to refuse to do anything which you consider is beyond your level of experience.