Thanks for the comment, louismcc.

I'd guess that there were 20-25 balls in Great Harbour on Peter Island, plus another 6 or 8 in front of the Ocean's 7 beach club at the west end of the bay. You shouldn't have a problem getting a ball mid-afternoon, as there's a lot of traffic to the Willy T just for lunch and then quite a bit of turnover during the afternoon.

There's one ball right in front of the Willy T with no pennant on it but if you can hook the eye on top and pull the (heavy!) chain up enough to slip your mooring line(s) through, you will be secure. Another option is to send someone out in your dink with two mooring lines and then pass those up to someone on the bow. Most people chose to pass by that particular ball, but it could be your backup plan if nothing else is open.

Have a great trip!