We took the KW cat sail/snorkel. There really wasn't any "sail". They "drove" the boat out to the snorkeling location. The snorkeling there was really good. The weather was a little stormy while we were there, but we still saw a lot of sea critters around the reef.
I can't imaging horseback riding in the caribbean (in the summer at least). To hot and humid - I'll take the ocean, thanks.
Snuba sounds like a lot of fun.
And that's what "I" think.