Tim Ingersoll
Contributor
ggunn:The waters off the southwestern third or so of the island (including the part where the Presidente is) has been designated by the Mexican gov't. as a Marine Park, meaning you can't take anything out of the water there and really shouldn't touch anything. This area includes a lot of reef area with its attendant life, but also a lot of boring sand flats; that an area is under the "Marine Park" designation doesn't necessarily mean that there is anything in particular to see there.
The shore diving at the Presidente is as good as it gets anywhere else on the island except maybe Chankanaab Park, which is to say that you'll see some stuff there but it won't be much compared to just about any boat dive that you will do.
Cheers,
Gordon does it justice. The snorkelling out front of the Presidente is pretty good as far as snorkelling goes but nothing compared to the worst dive I have done there. Be careful with your shore diving the boat traffic is constant and close to shore.