I understand that Belize is not in the gulf, however wouldn't the line from Key West to the western tip of Cuba to the Yucatan Peninsula mark the boundary of the gulf? And yes, including the Mexican coast as otherwise it would be too long a span with out rest stops. I know that at my age and condition, more than two days and one night of continuous sailing would be too much.
Actually, the dividing line runs from the Florida Keys to the the Yucatan Peninsula around Isla Holbox.
"When in command, command." -- Admiral Nimitz
Difference between a power boater and a sailor out on the water: A power boater is going some place special, a sailor is already there.
s/v Zotz 1981 Pearson 365 Ketch Hull #375