Quite a few memorable dives...but one of my favorites is a dive shortly after I was certified. My buddies and I were on a cattle boat in Southern California, and although the water conditions were tolerable, the weather topside was crap. Drizzly, breezy, chilly. All the small things that make a surface interval suck. That, plus a clammy wetsuit, made gearing up for the second dive deeply unpleasant.
But as soon as I splashed, everything got magical. The boat was right overtop of a canyon-esque split in a reef, and as I descended (in awful trim, like I was sitting in an easy chair), I slowly drifted past a sheer wall. Down, down, down...and the colors on the wall just went up, up, up... I was utterly relaxed, the water felt great, and the sight was gorgeous. It was super.