The primary advantage having a guide is seeing a LOT of critters. Jeff or Mark at Force E Riviera Beach just down from the bridge on Blue Heron are excellent instructors and guides. Scuba Jenny here on SB (she posted recently above) also guides! Or, simply show up at BHB 2 or 3 hours before hi tide on your day and talk to folks there-many will be students in groups, so ignore those and find some old salts, without big cameras probably; as many photogs work alone, and ask! There is a map of the snorkel trail on the beach near the lifeguard stand. All else failing, get in about an hour before hi tide just west of the marked swimmin' area and go south to the rocks, ie., snorkel trail, then choose to go east or west--then about 20 minutes or so before hi tide head northwest if going west. OR head NE if you went east on the trail. There is MUCH more trail going east than west. Have Fun!!