Go on a four-hour expedition ($85) with the Whale Shark and Oceanic Research Center that includes a short background lecture and the possibility of seeing the 20-to-40-foot-long fish up close in the water. After confirmation of a sighting, your driver will circle around and drop you off in the water. You’re not allowed to approach the gentle creatures as they glide beneath you, but they may rise and occasionally come close enough to touch. Though spring is considered the peak season, Utila is the only place on earth that has confirmed sightings every month of the year.
Arrange a rental from Kayak Utila (from $20 for four hours) to explore the dense mangroves surrounding the southern lagoon and traverse channels that cut through the inland to Rock Bay on the northern shore. Keep an eye out for wildlife like caimans, frigatebirds, and “monkey lalas,” Bay Island slang for basilisk lizards.
Explore the Mesoamerican Barrier Reef, the second-largest reef system in the world, which stretches from the Yucatán peninsula to the nearby island of Guanaja. If you’re not already certified, Utila offers some of the cheapest diving courses in the world; you can complete a course in a couple of days at the Bay Islands College of Diving (from $260 for PADI open water certification).
Explore the unspoiled and uninhabited island called Water Cay ($2.50 admission), where the beaches are nicer than Utila’s and the terrain is building-free. Water taxis ($25 each way) travel here, but book with Island Life Tours ($38) and let them prepare an open-pit barbecue for your group.