A fantastic (and very large!) Red-margin spanish dancer (Hexabranchus pulchellus)...the Hawaiian swimming crab (Charybdis hawaiensis) in the foreground--apparently ready for his closeup--will give you some scale.
A closer look at the Red-margin spanish dancer (Hexabranchus pulchellus)...
A pretty Red-spotted nudibranch (Chromodoris sp1-undescribed).