Took a look at the currents today. Wow, the Gulf Loop is extended way far NW (Ive run into it 160nm S of Mobile, AL before!) and there is an unusually strong eddie E of the
Yucatan Current. There is usually a weak eddie, but its really spun up now.
The same basic routing strategey would
work, but you could shift a bit E after rounding W
Cuba to catch the favorable side of the eddie (S setting current at over 1 knot).
I would stage from KW or the
Dry Tortugas (great place, highly recommend if you havent visited) and make the jump from there. An example
weather routing attached. You could make it as
single run and be in Rio Dulce in about 4-5 days depending on average speed.