One of our members was ramp-checked yesterday by Mexico's DGAC in Cancun, Mexico (MMUN). Amongst the specific items checked were:

Airworthiness Certificate
Registration Certificate
Insurance
Pilot License
Medical Certificate
RADIO STATION LICENSE
RADIO OPERATOR PERMIT
Raft & Life Jackets (it was an over-water flight)

If you are planning to fly to MMUN, you should be aware that you may be requested to demonstrate compliance with all applicable regulations which includes Radio Station License for the aircraft and at least a Restricted Radio Operator Permit for the pilot. If your flight is over water beyond gliding distance, Mexican regulations require laft raft and life jackets for all on board.

CST Flight Services (Formerly: Caribbean Sky Tours)
www.cstflightservices.com