Hummm OK Bean Hunter, This is a good contact for a local boat guide that will take you direct to San Pedro, trusted, tried and true.
[email protected] He's just down the beach from you in Xcalak. His name is Gallo (that means Rooster in Spanish). He's well connected on both sides of the border. The trip only takes an hour if you go by the front of the island . If the weather is bad you'll take the back route and that's about two hours.