Whale Sharks are considered an endangered species by the IUCN and by the Mexican government. Any activity related with this specie is regulated by the “Dirección General de Vida Silvestre”. This government institution releases every year a “Plan de Manejo” (management plan) that regulates the activity with this animal. You can read the full document valid for season 2022 here:   https://www.gob.mx/cms/uploads/attachment/file/721111/Plan_de_Manejo_TB_QRoo_Temporada_2020.pdf   About the specific concerns that you mention, you can see in page 17: The number of “entrances to the water”, per group of tourists will be a maximum of two (02). The maximum number of tourists accompanied by a guide will not exceed two (02). And in page 23 you can read: The schedule to carry out the sighting activity is from 7:00 a.m. to 2:00 p.m., and the maximum time per boat with the Whale Shark will be 30 minutes. Only one boat is allowed per Whale Shark and a maximum of 2 swimmers accompanied by a guide and when getting off the boat avoid making noise when entering the water.   The duration of the tour is between 6 and 8 hours. This depends on the time it takes us to get to the area, the time it takes us to find whale sharks and swim with them. All activities during the tour have variable durations because we are dealing with nature, and this makes it different every time. Like you mention, the visibility at the snorkeling spot is not always good and this is unpredictable.   The maximum number of passengers per boat is 10. We operate two boats for 10 passengers and one for 8. The distribution is made according to the capacity of the boat. We also offer private tours, so if you saw a boat with less passengers, it might have been a private service.   We are very aware that the only way to ensure that this activity can continue to be done in the future is by following the rules, even though they may seem questionable for some of our passengers.   Our guides take frequent training courses and receive updated information about the whale sharks every year, including their biology and ecology. This a is requirement to have the NOM-09-TUR-2002 official certification, which all our guides have. We are sure that they can solve any doubt that our passengers might have and will make sure that they always let our passengers know this, so that those who want to learn about more specific aspects do not hesitate to ask.