This is one of my very favorite critters to find. They are only about 2 inches long so they are not easy to spot. Generally they are not that common in So Cal at shallower depths either (i have only found one on about 3 other dives in the past). At this spot though, the Farnsworth Bank, in 75 feet of water 2 miles off the windward side of Catalina Island, California, these nudibranch were everywhere. You couldn't turn around without seeing another, or 2 or 5 all in one spot! A marine life nerd's wet dream.