Just off the tip of Mexico’s Yucatan Peninsula is a small island untouched by mass tourism. Peaceful Isla Holbox might go unnoticed entirely, except for some high-profile visitors that frequent its warm ocean waters each summer. Averaging 40 feet long and weighing 15 tons, the whale sharks' presence is hard to ignore. These gentle filter-feeders are actually not whales at all, despite their size, but the world’s biggest fish! We enter the water with them in pairs, alongside our Expedition Leader, for a low-impact, close-up encounter. If you’re looking for a fish tale to top all others, this is it!