Having sailed Texas to Cancun on a 41 footer. We aimed more toward Progreso in the Yucatan because the current coming between Mexico and Cuba (what is the beginning of the gulf stream) was blocking sailing straight. Also we had SSE wind predominately so were jammed hard on starboard tack. Once arriving in Progreso (Yucatan) we then sailed to Isla, then Puerto Moreles. We left Texas just about this time of year.
Cancun is near Isla. When returning home flew out of the Cancun airport
Clearing customs in Progreso was MUCH less hassle than it would have been in Isla. The agents all came to the boat, filled out forms and flatly refused ANY money. we went to the bank to pay for and get the tourist permits. Arriving in Isla, the harbor master was PO'd that he couldn't charge us what he had planned, as we were already entered.
All in all a decent sail down.
Have fun