I went with these guys as did some frineds from Charleston before me. Boated a good number of juvy tarpon, guide was really good, they are right in the tourist hotel section of town and you are fishing within 10 minutes from launch (if you fish the lagoon for its youthful tarpon). There are also permit in these waters. Ten weight is recommended for these poons. Most that I boated were 30-40 pounders and I jumped one near the entrance of the lagoon to the open ocean that guide said topped 100 lbs. Check em out especially if you don't have a lot of time to travel south down the coast or north to holbox
http://www.cancuntarponfishing.com/index.html