Palenque is a 6 months fresh airport so no piston engine fuel is available yet, only jet. Our plane is certified to use automotive fuel but security won’t let us bring flammable substances through the terminal so I had to take off with 10 gallons and fly over marsh land and swamps to the nearest airport with fuel – Ciudad del Carmen. 45 mins flight would need 6-7 gallons (considering 8-9 gallons per hour burn rate) so I had just 30 minutes of reserve – not too much room for navigation errors. Fortunately VORs and GPS worked well and we landed in MMCE still under power :-). From there a low flight under tropical showers and finally arrived at a tiny airport in Playa del Carmen, completing the first segment of our trip without incident!