Saint-Martin or US Virgin Islands?

Both are first-rate beach destinations, but the US Virgin Islands come out a little ahead, mostly thanks to St John. Trunk, Cinnamon and Maho bays sit inside the national park with reef just offshore, and Magens Bay on St Thomas adds a long, sheltered curve of sand. In winter the north shores can pick up swell, and then the south-facing coves are the calmer swim.

Saint-Martin fits a lot of variety into a smaller space. Orient Bay is the long, social beach with sunbeds and water sports, while Baie Rouge and Baie Longue on the leeward coast are quieter and very clear. Le Galion's reef-sheltered shallows are the gentlest. Its Atlantic-facing bays sometimes collect seaweed, so in some months the west coast is the better bet.

Saint-Martin eats noticeably better. Grand Case alone is worth the trip for food lovers, with waterfront French and creole restaurants on one side and the lolos' grilled lobster and ribs at shared tables on the other. The French side's bakeries and supermarket cheese and wine also make self-catering a pleasure.

The US Virgin Islands have a real West Indian kitchen of kallaloo, fungi, goat stew and pates, but you find it at roadside stands and food fairs rather than in restaurants, and it is strongest on St Croix. Around the St Thomas resorts and Cruz Bay, menus lean towards American dishes made for visitors.

The US Virgin Islands have much more history on show. Nearly two centuries of Danish rule left Christiansted's protected arcades and fort, Charlotte Amalie's stepped lanes and its sand-floored synagogue of 1833, and plantation ruins such as Annaberg and Whim that tell the sugar and slavery story.

On Saint-Martin, the sights come down to Fort Louis above Marigot, a few streets of balconied creole houses and a small museum, which most visitors finish in a morning. Neither is a cultural destination, but the Virgin Islands give you several outings to Saint-Martin's one.

Evenings are equally low-key on the two, but they differ in what a late night means. Saint-Martin's French side is about long dinners and a drink in Grand Case or at Orient Bay's sunset bars. Anyone who wants to dance past midnight crosses to Simpson Bay and Maho, where there are proper clubs and casinos.

The US Virgin Islands have no real club scene. The liveliest evenings are in the open-air bar strips of Red Hook and Cruz Bay, full of charter-boat sailors, and most nights end early. The exceptions are St Thomas carnival and the Crucian Christmas festival, which keep the streets busy late for weeks.

The US Virgin Islands offer more to do outdoors, both on land and at sea. Park land covers most of St John, and the Reef Bay trail runs down through dry forest past petroglyphs to the shore. Offshore there are protected reefs, Buck Island's underwater trail, some of the Caribbean's most sheltered sailing water and the bioluminescent bay at Salt River.

Saint-Martin's outdoor offer is pleasant but smaller. You can climb the forested trails up Pic Paradis at about 424m, snorkel with turtles and rays in the Tintamarre reserve, and kitesurf in Orient Bay's steady trade winds.

Saint-Martin is the better place for island-hopping. Anguilla's quiet beaches are a short ferry from Marigot, polished St Barths is a longer crossing, and the small volcanic Dutch islands of Saba and Sint Eustatius make a full day out. Philipsburg and the low-flying planes at Maho are also an easy half-day on the island itself.

From the US Virgin Islands, the classic outing is the ferry from St Thomas to St John. The British Virgin Islands are within reach but need a passport and depend on ferry schedules, and St Croix is too far away for a day trip, so the choice is narrower.

The US Virgin Islands are the easier choice with children. At Maho Bay on St John, turtles feed in water shallow enough for young snorkellers, and the Coki Point marine park adds touch pools and an underwater observatory. For American families, the familiar currency and no need for a passport make the trip simpler.

Saint-Martin has its own gentle bays in Le Galion and Pinel, plus villas with kitchens and pools, but it has less made for children beyond a treetop park. Both have hilly, narrow roads, so a self-contained resort or villa saves a lot of driving with tired children.

Getting around is about as awkward on both, but in different ways. Saint-Martin is a single island where nearly everyone hires a car, the minibuses suit hops between towns better than beach days, and the unmarked Dutch border is just another stretch of road.

The US Virgin Islands are split across three islands. Open-sided safari taxis cover the routes between towns and beaches on St Thomas and St John, ferries link the two easily, and St Croix is a separate flight away. Driving is on the left, in American cars.

Shopping is similar on the two, and each has a duty-free street built for cruise passengers: Front Street in Philipsburg and the old Danish warehouses along Main Street in Charlotte Amalie, both full of watches, jewellery and liquor.

Where they differ is in what is local. Saint-Martin adds Marigot's waterfront market of spices and fabrics, French boutiques and guavaberry liqueur. The US Virgin Islands lean towards island-made crafts, with the studios at Mongoose Junction and in Christiansted and St Croix's hook bracelets.

Both are expensive, and the cost is high in winter on either. The ways to save differ, though. On Saint-Martin, the lolos and supermarket picnics are what keep the food bill down.

In the US Virgin Islands, St Croix and the campgrounds on St John are the cheaper places to stay, and the beaches and park trails cost little or nothing. Per-person safari taxi fares add up quickly for a family.

The US Virgin Islands have more of a music culture of their own. Quelbe scratch bands, steel pan and the mocko jumbie stilt dancers have deep local roots, and the university amphitheatre on St Thomas hosts touring concerts and dance from time to time.

Saint-Martin has no stage at all. Its music is the zouk, soca or reggae band playing over dinner in Grand Case or at a hotel, with Carnival as the one big moment of the year.

Neither has a spa tradition, so rest on both comes down to resort spas, some yoga and a slow pace. The US Virgin Islands do quiet a little better. St John and the east end of St Croix have little traffic and long, shaded afternoons, well away from the cruise crowds of Charlotte Amalie.

On Saint-Martin, a villa above Anse Marcel or a cove on the west coast is the place to switch off. Traffic around Marigot and the lagoon bridges can break the calm on days you have to drive.