We took the scooter south about 10 minutes, so less than three miles, I'm sure. Tours do this as a bike ride in a half hour, too. We found a secluded spot at the south end of the property at the mouth of one of the underground river caves and "dropped" to snorkel - cold, cold, till "riverwater meets oceanwater" a few yards out (strong current out, too). There's a nice variety of fish and no 'contrived" setting so that you see some places.

Dolphin "experience" is the money maker at $75 to $150 per person depending on what you want. Call in advance to book this. We swam around the dolphin area hoping for a glimpse, but all "curtained" off from the general public. People are nice and helpful.

Chankanaab also was our pick for souveniers - decent prices, no pressure. Felt safe at all times everywhere we were on this island, all day, walking or driving.