Haven't done TX to Isla, but have gone from Florida
to Isla, then back six years later. We found the best cruising guide to be Freya Rauscher's "Cruising Guide to Belize
& Mexico's Caribbean
Coast Including Guatemala's Rio Dulce. The 2007 version is better than the 1996 version - 1996 had some incorrect waypoints - we had it but were warned to use her bearings and navigational information, but not her waypoints. I assume she's corrected that in the 2007 edition. We know boaters that have gone from Kemah
TX to Isla -- try s/v Bruadair's blog
. They're in Panama
now, but started in Kemah
, were our buddy boat from the Bay Islands to Bocas Del Toro, Panama and one season in the San Blas, Panama. I'm sure Damon could answer questions. Buena Suerte!