You could scuba yourself into the plankton-y depths surrounding Mount Desert Island in search of starfish, lobster and other saltwater denizens, or you could get a guided tour from the most entertaining deep-sea diver in Bar Harbor. Diver Ed is part educator, part adventurer and part clown, taking an underwater camera into the coves and ledges as his wife Edna — otherwise known as Captain Evil — narrates topside. The real fun emerges when he surfaces with the very creatures that passengers got a glimpse of onscreen, offering kids the chance to hold, pet and kiss crabs and sea cucumbers on deck. Not for the faint-of-heart or humor-challenged, Ed’s narration runs to scatological, particularly favoring close up views of sea cucumber butts — but he has a unique gift for connecting with kids of all ages over the wonders of the water. (Tours generally leave at 9:30 a.m., 1:30 p.m. and 5:30 p.m. daily, meeting outside the Dorr Natural History Museum on the campus of the College of the Atlantic, 15 minutes before start of the tour.)