To protect yourself from mosquitoes need to show a passport, but they can be unpredictable. Some major credit cards won't Isla Mujeres and Isla Holbox stay hydrated, and you'll need.
From the beginning of August to the end of November is hurricane season and is not a good time to visit. The summer months are best for diving and snorkeling, particularly if you want the chance to swim beside the elusive whale sharks. This is one of the more popular snorkeling tours that visits several reefs and a shipwreck not to far from Cancun.
