What a hidden gem!!
Geroge's Island is awesome! It costs $10 for the ferry over, make sure you're getting on the fast boat, 20 minutes, instead of the slow boat, 45 min to an hour. Once you're there you can expolore the island, camp, go inside the fort - you may want to bring a flash light for that. Then you can also take free boats to the other islands around George's and they are all beautiful. I would make it a day trip, so nice!