I'll be there in January, first time for me...similar situation, looking for a beach day. From what I've read the first thing is getting off the ship, our ship arrives at 10am as well. Passengers with ship booked excursions get off first, a post from a cruise last week that stopped in GC stated that they did not have an excursion or priority and didn't get off the ship until close to noon.... What I decided to do is a 2 hour snorkeling excursion starting at 10:30am (hopefully first off) back to port at 12:30 and then off to the beach. Not a lot to chose from as far as "beach clubs" seems like Coral Beach is about the only option I can see that serve food and drinks and have facilities to use, so that as of now is the plan. Public beach seems like another option with less services (food, drink, restrooms) I've read that Coral can get crowed, but crowds do not bother me.