What a great set of pictures.

I did not realise that we had Nudibranchs in UK waters. I guess one of the many things I do not know. I particularly like No. 3. I am looking forward to the next set.
Just to satisfy my curiosity can you post a picture of your underwater set-up. Not that I am planning to do any myself it is far too cold in UK waters for me to even put a toe in.