Nudibranch

Thanks, Leuba. There's a large number of species which live in very shallow water so they're often missed by divers (most of whom think that diving shallower than 10 meters is not "real diving") and also by snorkelers and free divers (most of whom can't really spend enough time underwater to look for very small creatures). Too deep for some, too shallow for others, these species stand in a sort of "depth limbo". But some also have strange habits like being more active in the winter when there are few people willing to dive. So you have to actively look for these animals and study their habits before you see them.

Great job - Congratulations !