Isla Mujeres is quickly becoming the new whale shark capital. They discovered there is a whale shark aggregation happening out in the blue waters a few years ago and it's grown and grown where Holbox is becoming second fiddle to Isla Mujeres, much to the displeasure of the locals of Holbox. Big difference is the amount of whale sharks you will interact with which is usually dozens upon dozens if not even hundreds and the water is blue and much more clear. The ride is longer and the waters rougher, but there is no comparison between that linked video and what you see in the new area. Go to youtube and type in "Isla Mujeres whale sharks", and you will see what's going on. This is effectung the economy somewhat of Holbox, the locals are quite vocal and pissed off about their rivals on Mujeres. I've even been lied to by Holbox tour companies in desperation to keep the business there. So if you feel bad for Holbox, you can still book with them and help them out.