I was just down in the area and had a good trip for tarpon and snook at Isla Blanca...just north of Cancun. Yucatan Flyfishing adventures runs a pretty good outfit in the area, and I recommend them after my trip. Fish on your own options are possible along the beaches in front of the hotels if you're in less populated areas....the inhibiting factor is wind direction and surf. While I was there I talked to a couple guys that caught a few bonefish walking the beach. Something to chew on. Happy hooking!