Tom M wrote in message Can anyone tell me if airliners typically use HF
radio on this route?

There is good VHF coverage over the Gulf in the flight levels. Low level
aircraft will typically relay position reports to overflying aircraft.
Nearing the Yucatan, the VHF coverage is comparable to service in the US.
The only times I used HF over the Caribbean were for sending company
messages and for setting my watch.

D.