From whale shark sightings to jungle hiking, the Bay Islands of Honduras feature a spectacular underwater environment and a fascinating variety of topside ecological and cultural experiences. This archipelago, consisting of three main islands, three islets and 60-odd keys, lies 35 miles off the coast of Honduras. The islands are steep, with narrow coastal shelves and rocky spines carpeted in tropical rain forests. A series of bays and lagoons punctuate palm-lined coasts, creating scenic beaches bordered by iron-shore outcroppings. The islands are steep, with narrow coastal shelves and rocky spines carpeted in tropical rain forests. A series of bays and lagoons punctuate palm-lined coasts, creating scenic beaches bordered by iron-shore outcroppings.Offshore, narrow fringing reefs provide miles of precipitous walls and coral gardens, close enough in many places for easy shore diving. The nearly continuous walls are remarkable for shallow drop-offs that often start within 25 feet of the surface. These walls also feature an assortment of corals and sponges. Sixty-two of the 64 known species of stony corals have been identified in the Bay Islands. Sponge species are uncountable and assume every color and shape found in the Western Hemisphere. Three excellent freighter shipwrecks -- one off Roatan's Sandy Bay, another in front of Utila's harbor and a third off Guanaja's Southern Coast -- add spice to Bay Island diving. English and Spanish are spoken by the majority of locals. These residents of English, Scottish and African descent inhabit quaint seaside villages consisting mostly of stilt-house architecture. Here's a look at what the three largest islands have to offer visiting divers: UtilaCharming Utila is as pleasant a destination as can be found in the Caribbean. Flatter, closer to the mainland and the smallest of the main island trio, it is perfect for hiking, bird-watching and diving.Perched on the continental shelf, Utila is ringed by a near-shore fringing reef and coral pinnacles, as well as an offshore barrier reef with a steep drop-off. The result is a superb variety of diving experiences highlighted by the island's signature attraction: the waters off Utila are part of a migration route for whale sharks.GuanajaGuanaja, the second largest of the Bay Islands, is an ideal tropical getaway. With a sparse population and three villages accessible only by boat (there are no roads on the island), Guanaja embodies the look of the old Caribbean. Jungle trails wind through the island's mountainous heights, passing scenic waterfalls and ancient habitations strewn with pottery shards.The reefs surrounding Guanaja are like a true barrier reef -- they are situated well offshore and are only occasionally interrupted by deep passes, creating impressive inside and outside walls. A special attraction for divers in Guanaja is the clusters of black and white crinoids that often are sighted on coral pinnacles. There are also lava caverns that create a labyrinth of swimthroughs.The best snorkeling and shore-diving beach is in front of the Bayman Bay Club on the island's northern coast. Posada del Sol, a plantation-style resort on the opposite coast, provides the easiest access to the huge Jado Trader, a shipwreck resting in 110 feet of water. Hiking, sea kayaking and town tours complement the excellent diving on beautiful Guanaja.RoatanThe largest, most populated and most developed of the Bay Islands is Roatan. Convoluted walls lining both long coasts characterize its reefs. There are also hundreds of shallow fringing and patch reefs, some of which are perfect for snorkeling or night diving. A dozen mid-sized to small dive resorts provide easy access to docks and reefs. On the northwest end of Roatan is the tourist community of West End, a seaside grouping of inexpensive accommodations, funky bars, restaurants and an excellent sea kayak operation.The Roatan Institute for Marine Sciences at Anthony's Key Resort features a variety of recreational and educational activities, including daily dolphin presentations, dolphin snorkel and scuba experiences and kids and adult dolphin camps and programs. Informational displays on the island's ecology and history are housed at the Roatan Museum in the institute's main building. The institute also offers marine life courses for children and adults. Cultural experiences include tours to the Garifuna village of Punta Gorda and a visit to Roatan's Wildcane Historic Village at the Bay Island Beach Resort. Directly off the beach, groups are escorted through a juvenile nursery and shallow coral reef on the Roatan Natural Aquarium and Snorkeling Trail. Operation Hardshell is a sea turtle rescue and habitat program based at the CoCo View Resort that has released 500 turtles back into the environment since 1997.