MIAMI HERALD | SUSAN COCKING Diving Haven Exists in Mexico XCALAK, Mexico — Warning: Avid tarpon anglers, don’t even think about using sinking fly lines, live mullet, or a Lefty Deceiver. These tarpon are for viewing only – not for catching. About 100 of them were lazing around, spa-like, about 60 feet deep in a coral-lined canyon less than a mile off this tiny town on the southern tip of the Yucatan Peninsula when I visited last summer. The canyon is part of a marine sanctuary implemented about two years ago for the lands and nearshore waters of Xcalak, a Mayan word that means “two together,” named for two natural cuts through the barrier reef. The spot frequented by the tranquil tarpon is called La Poza, or freshwater spring — a place they go to chill out and have their gills cleaned by gobis and remoras. “I’ve never seen them…READ MORE