St John or Vieques?

Both islands have warm, clear water and white sand, so the real choice is how you want to spend a beach day. On St John the sheltered bays follow one another along the north shore road, kept free of building by the national park. A safari taxi from Cruz Bay reaches most of them in minutes. That ease brings company, and in winter the best-known bays are full by late morning, so an early start pays off. The quieter, rockier coves are on the dry south and east sides around Coral Bay.

On Vieques the calm water is on the Caribbean side, along the south coast within walking or cycling distance of Esperanza, while the Atlantic north can turn rough in winter. The finest sand is at the eastern end inside the wildlife refuge, down bumpy dirt tracks that need a jeep, and there you may have a reef-fringed bay to yourself. Neither island has much on the sand, but on Vieques you are much further from help if you forget water or shade.

Neither island is a place to travel for food, and both rely on ingredients shipped in. The cooking differs. Cruz Bay gathers St John's open-air grills, beach bars and a few West Indian kitchens serving johnnycakes, saltfish and stewed goat.

Vieques eats Puerto Rican: mofongo on Esperanza's seafront, alcapurrias and empanadillas from roadside kiosks, and bakeries in Isabel Segunda. Many of its kitchens close for days at a time out of season, so self-catering is the safer plan there.

St John has a little more history to walk through, all of it outdoors. There is the Annaberg sugar mill above the north shore, the Taíno petroglyphs at the bottom of the Reef Bay Trail, and the fort ruins at Coral Bay where the 1733 slave revolt began. Together they fill a morning or two.

Vieques covers its story in an afternoon. The one museum is in the small Spanish fort above Isabel Segunda, and its account of the island's decades as a naval bombing range is the most striking local history either island offers. Lighthouses, plantation ruins and the old ceiba tree make up the rest.

Neither island has clubs, but St John stays up a little later. The open-air bars on the Cruz Bay waterfront mix boat crews, residents and visitors until late evening, and St Thomas is a short ferry ride away if you want more. On Vieques, evenings mean rum punch along Esperanza's seafront and the local bars of Isabel Segunda at weekends. For many visitors the only reason to go out after dark is the kayak trip on the bioluminescent bay.

St John is the stronger island for the outdoors. Its national park is steep, dry forest dropping to reefs and headlands, and you can walk it on proper trails like the Reef Bay valley, Ram Head and the Lameshur loops. The snorkelling at Waterlemon Cay and the seagrass at Maho Bay is excellent.

Vieques has one sight that St John has nothing to match: Mosquito Bay, where every paddle stroke glows blue-green on a dark night away from the full moon. The rest of its wildlife refuge is gentler, with salt ponds, lagoons, birding, wandering horses and easy reefs, but its low, scrubby hills offer nothing serious to hike.

St John sits in the middle of an archipelago, and that shows. St Thomas, with the Danish streets and fort of Charlotte Amalie, is twenty minutes away by ferry. Charter boats go across to Jost Van Dyke, Tortola and The Baths on Virgin Gorda, with a passport for the border.

Vieques is an island you stay on. Culebra and Flamenco Beach are the one rewarding outing, and you need a chartered boat to get there. Old San Juan is a long day there and back.

Both islands suit families who are happy to spend their days in the sea, and neither has anything built for children. On St John, small swimmers can stand in Maho Bay with turtles nearby, and Trunk Bay's marked trail is an easy first snorkel. The downside is the journey of flight, taxi and ferry, plus steep roads up to the villas.

On Vieques, the horses by the roadside win over younger children, and older ones remember the night kayak on the glowing bay. Medical care there is limited, though, the ferry adds effort, and the beaches have no lifeguards or shade.

St John is the easier island to reach and to get around. From St Thomas it is a taxi to Red Hook and a short, frequent ferry. Once there, safari taxis run to the north shore beaches and Cruz Bay is walkable, though driving means steep switchbacks on the left-hand side of the road.

Vieques takes more organising. Ferries from Ceiba can sell out or change schedule, so many people fly in on small planes. The refuge beaches are at the end of rough dirt roads, and the few jeeps for hire need booking well ahead. Shared públicos only cover the run between the ferry and Esperanza.

St John has the edge for browsing, partly because of what lies across the water. The courtyards near the Cruz Bay ferry dock have galleries, jewellers making hook bracelets and resortwear boutiques, enough for an hour, and the duty-free streets of Charlotte Amalie are a short crossing away. On Vieques, shopping means a few small galleries in Esperanza and Isabel Segunda, and otherwise the grocery store.

Both are expensive, but Vieques costs noticeably less. Its simple Esperanza guesthouses, self-catering and the cheap ferry give a budget traveller real ways to save, even if jeep hire is hard to avoid.

St John is one of the pricier places in the Caribbean in winter. Villas, restaurant meals, jeeps and ferries all add up. The Cinnamon Bay campground and the summer and autumn rates are the main ways to save, and those are the hurricane months.

Neither island has a theatre or concert hall. Live music on both means a guitarist or small band at a seafront bar. The big events come once a year and differ in flavour. St John's carnival in early summer brings calypso, quelbe and steel pan. Vieques has its patron saint festivities in Isabel Segunda, with Puerto Rican bomba, plena and salsa in the town square.

Both islands offer quiet rather than treatments: little traffic, no high-rise building and no spa culture. St John adds a bit more pampering, with therapists who come to the villa and treatments at its resorts, all against nights of tree frogs and hillside views. On Vieques, the calm is simpler: guesthouse yoga, a villa pool and long, empty afternoons with roosters for company.