looks pretty close, but have no idea how far I heard that Isla is the closest point from Cuba, and that is the reason for the militia on the island.
I think, without looking it up, it's around 120 miles from Cuba to Isla. My understanding is that Isla is the closest point to Cuba in Mexico and also the southern tip of Isla is the highest coastal point in the region. You will often find some militia patrolling this area looking out for boats bringing illegals. Due to the wet foot dry foot law, Cubans can get into the US if they arrive via land and this is the easiest/shortest path for them. (I'll move this to the main Cancun forum, you'll probably get more input to this thread there)
The westernmost point of Cuba is about 100 miles (Havana is a way inland). http://wikimapia.org/5109972/Westernmost-point-in-Cuba Pinar del Rio is to the extreme west, it's the closest airport at 305 km/189 miles from Cancun airport. http://www.ourairports.com/airports/MMUN/closest.html (Yes, I was recently looking for the same info).
