Hi, Kat --
We're thinking about doing the same trip from Ft. Lauderdale, first to Isla Mujeres and then south through
Belize, eventually to the
Panama Canal and then to the Pacific side. Leaving late November/early December (depending, of course!). I've been researching the
route and using Pat Rains, "Cruising
Ports: The Central American Route" (2009 update) and Freya Rauscher, "Cruising Guide to
Belize and Mexico's
Caribbean Coast" (Third Ed, 2007). The very nice thing about Rauscher's is that she includes two
charts she personally updated for the Mexico/Belize coast, where updated "official"
charts really don't exist.
If going to Isla Mujeres, it is 335 nm from
Key West on a rhumb line. Rauscher suggests sailing 267 true for 66 nm from Key West until you are 14 miles south of the
Dry Tortugas and than sailing direct to Isla Mujeres. You're sailing along just outside of the Cuban territorial waters much of the way.
The
Yucatan Channel may well be the most difficult part, since lots of
water is flowing south to north and if you get a norther from the US, the seas will get very high, very quickly; steep and short periods. She suggests that the best time to cross is right after a strong norther blows itself out.
Assuming a 6
knot average speed, that's about 60 hours from Key West to Isla Mujeres. We're in a 44' cat and can usually do better than that, but I still tend to use it for planning purposes.
From my look at things, the route around the eastern side of
Cuba has its own challenges and there are several shoals on the way that can be challenging, not to mention it is simply much farther to go before you hit the cruising grounds. Of course, you would be able to see
Jamaica and Cayman.
Hope this helps!
ID