Good snorkeling at Cistern Point, nice restaurant and a laid back beach with the only people there generally being from the resort and from moored boats. Great rum bar too with several different rum flights to try and/or tasty and creative mixed concoctions. If conditions aren't too bad and you are confident in your dinghy you can take it over and explore Salt Island (bring a handheld VHF with you of course). We took the dink all the way to the Rhone on our last trip and it was nice not having to stop there with the big boat. Also, Cooper is a great jumping off point for getting to The Baths the next morning before the masses. Wake up at sunrise, slip the mooring line off and motor over while the rest of the crew is sleeping.

You've been made aware of the issue if there is a North swell. As other have said, do get there early or you'll likely find yourself in a race with three other boats for the last mooring ball - which you'll discover is missing it's pendant when you get to it. Anchoring isn't good at Cooper and most charter companies don't allow it there.

Matt