Rules for protecting whale sharks

From the Web site of Serious Diving:

The creation of the Whale Shark tourism industry in this area of Mexico [Isla Mujeres] was carefully designed to be eco-friendly and to provide protection for participants and the Whale Sharks themselves. Prices, season dates and rules are set by the controlling bodies and are strict and heavily enforced. Our tour services are fully licensed and adhere strictly to the rules. Violating the rules not only puts you in danger but also endangers the animals and their ability to sustain their habits.

If you decide to use another provider, be sure to verify that they comply with all rules listed [on the Web site]. The Mexican Army is charged with enforcing rules and can detain non-compliant boats who do not comply with the rules. We want everyone to have a fun, exciting and ultimately safe tour no matter which provider they choose.

DO NOT BOARD TOURS USING DIESEL ENGINES, THE RESIDUE HARMS THE WHALE SHARKS!

Beware of anyone offering you a price below the legal standard or who claims they will allow you to violate the rules below. No one wants to waste a day of their vacation or hard earned money with a spoiled trip.

Support your local tour operators by booking directly with them rather than with large tour operators!