I like to get on one of the catamarans out of Fajardo that sail to Iccacos and Lobos for about 4 hrs. They give you all the rum punch you want and a decent deli sandwich for lunch. The first stop the cat wedges itself to the beach and you can snorkle around. The second stop is a mooring ball on 20 ft of water and again you can snorkle around the boat. I have alwasy sailed Spread Eagle, but there are a few others that have the same schedule 10 am - 2 PM. When you get to the airport get a copy of the Que Pasa magazine as they often have discount coupons for the daysails.