Vieques is a small island off the east coast of Puerto Rico, about a 30-minute ferry ride from Ceiba. For decades it was used as a US Navy bombing range, which kept most of the island undeveloped. Since the Navy left in 2003, large sections have been turned into the Vieques National Wildlife Refuge, and the island has become one of the Caribbean's most appealing low-key destinations.
The main draw is Mosquito Bay (Bahía Bioluminiscente), one of the brightest bioluminescent bays in the world. On a dark night, the water glows electric blue with every movement — swimming or kayaking here is genuinely magical. Tours run most evenings; go on a moonless night for the best effect.
The beaches are exceptional. Sun Bay is the most developed (which is not saying much — there is a parking area and some shade trees). Red Beach and Blue Beach, inside the refuge on the former Navy land, are wilder and emptier. The snorkelling is good, particularly along the southern coast.
Isabel Segunda on the north side is the main town, with the ferry dock, a few restaurants, and a small fort (Fortín Conde de Mirasol). Esperanza on the south coast is the laid-back strip where most visitors eat and drink, with a waterfront malecón and a handful of bars.