Water is getting warmer, although may be a relative thing as he did give up a skiing weekend for this. As I got me feet wet watching him in the rough surf, it wasn't too bad.
This one scanned from one of the Extacolor 5254 slides. I would have been using Spiratone close-up filters on top of the Nikor lens. Not nearly as crisp as with a good macro lens, but back then my budget was quite limited and macro lenses were very expensive.