We loved it! Details on how it goes. - I had so much fun! The ride - I really appreciate they were willing to come out to Costa Mujeres to get us. Not many companies were willing that I could find. The marina - you can change at the marina. Be sure to use the bathroom because there is not any bathroom on the small boats and you're on them for around 3 hours. They offer a pastry to eat before leaving. The boat ride - very bouncy (which I loved). We had 8 total people on our boat, 4 couples. It was really great having such a small group without children!! It took over an hour to get to the location of the whale sharks. Same amount of time to come back but we stopped at Isla Mujeres. Have plenty of sun protection with you. The cool part - you must wear either a life jacket or rent a wet suit. They provide snorkel equipment on the boat. We went in one couple at a time, jumping from the boat (about 2 feet of a jump). The Capt would line up with a whale shark and you'd jump in, with the swimming guide, towards the front of the whale shark but at least 6 ft away. The swimming guide had a go pro taking pictures and videos throughout. He also made sure we were seeing as much of the whale shark as possible. They are fast, but you can use your flippers to swim alongside it for a few minutes. Once it swims away or dives down, the guide helps you get back to the boat where you have to climb up back into the boat via ladder. Again, pretty bouncy. Each couple repeated this process a few times. The ride back - just as bouncy and lengthy as the ride to the whale sharks. However, you still at Isla Mujeres and can jump into the gorgeous water and swim. It's not deep. We were on the water for about 30 minutes and the guide took more pictures with his GoPro. This was a really nice part of the tour to wind down and soak in what we just got to see. The lunch - when we were back on the boat they gave us ceviche and a ham and cheese croissant sandwich. Both were good. I really love ceviche in general, but this was really great! I ate all of mine and got seconds. The end - it was a short ride back from Isla Mujeres to the marina. Once back, you can view and purchase the pictures and videos they took. It's pricey, but we planned for it. They also sell a few souvenirs. If you do purchase the pics/vids, they give you a SD card before you leave and later email you a link to download them. We were then taken back to our hotel. Need cash for the marina fee ($20usd ea) and tips for driver and the boat guide and Captain. Can use card for wet suit rental, souvenirs and pics/vids. We had a blast!!! Everything was pleasant and fun!

Swimming with Whale Sharks - Highly recommend. Great experience with friendly English and Spanish speaking tour guides. No bathrooms on the boats though so plan ahead.