I've enjoyed snorkeling off of the Sosua beach several times. Be sure to bring a disposible underwater camera with you. The beach is very long, and in my opinion, the best part of the reef is about two-thrids of the way down. I wish I could remember the booth number of "Wendy's Bar", but I cannot. If you find "Wendy's Bar" (again, I'd say it's probably two-thirds of the way down the beach), ask for "Dario". Dario will rent you beach chairs and take care of you while you're at the beach. He will sell you ice-cold bottled beverages, arrange for rental of snorkeling equipment (from "Blanco"), and will keep your belongings safe while you snorkel (he'll store them behind the bar while you're snorkeling, and bring tem back to you when he sees you come out of the water). I spent a beautiful afternoon there last spring. The chair, snorkeling equipment, banana for the fish, and two Presidentes (one large, one small) cost me a mere $8 US. Dario is a very friendly, attentive, and trustworthy man. I do not use a snorkeling vest, but it sounds like a great idea...swimming out to to the reef can be pretty tiring. One last tip... as you swim out, turn around and note the landmarks at your part of the beach (colors of the chaise lounges, umbrellas, etc.)... otherwise, you may find it difficult to find your place on the swim back.