St Croix or Saint-Martin?

The two are evenly matched for beaches, but the beaches feel different. St Croix's best sand is at the quiet west end, where Sandy Point and Rainbow Beach have long, calm stretches with the sunset in front of you. Cane Bay on the north shore is the place to snorkel from the beach, and some east-end coves can only be reached on foot over the hills.

Saint-Martin packs more good beaches into a smaller space, and they cover a wider range. Orient Bay is the busy one, with sunbeds, water sports and a clothing-optional end. Baie Rouge and Baie Longue on the west coast are clear and calm. Seaweed sometimes drifts into the Atlantic-facing bays, so in some months it pays to head west.

Saint-Martin eats noticeably better. Grand Case alone puts French and creole dining rooms over the water next to open-air lolos grilling ribs and lobster, and the bakeries and supermarkets carry proper French bread, wine and cheese.

St Croix's strength is Crucian home cooking: johnny cakes, kallaloo, goat stew with fungi, and roti from roadside stands in Frederiksted and out in the countryside. Its restaurants, mostly in Christiansted, lean towards fish and mainland American food. The rum distilleries near Frederiksted are worth a visit.

St Croix has far more history to explore. Christiansted's arcaded ochre waterfront, the Steeple Building and Fort Christiansvaern form a preserved Danish colonial town. Frederiksted's red fort, where emancipation was proclaimed in 1848, sugar-mill ruins across the hills and the Whim estate museum fill out the story of slavery and sugar.

On Saint-Martin, the ruins of Fort Louis above Marigot, a few streets of balconied creole houses and a small museum are about all there is. It makes a pleasant morning rather than a reason to come.

Neither island is known for nights out, but Saint-Martin has the livelier evenings. Grand Case has street music on busy winter nights and terraces that stay open late. When you want more, the clubs and casinos of Simpson Bay and Maho on the Dutch side are a short drive across the open border.

St Croix has nothing comparable. Evenings mean rum drinks in the boardwalk bars and old courtyards of Christiansted or sunset at a beach bar, and most places close well before the small hours. The exception is the Crucian Christmas Festival, when parties run late.

St Croix has the better outdoors, and most of it is underwater. Buck Island Reef is a national monument with a marked snorkelling trail through elkhorn coral. The Cane Bay wall drops into deep water close to shore, and the bioluminescent bay at Salt River can be kayaked at night. On land there are dry, grassy hills out to Point Udall, a patch of rainforest in the north-west, and leatherback turtles nesting at Sandy Point.

Saint-Martin's offer is pleasant but smaller. There are forested trails up Pic Paradis, reef snorkelling around Tintamarre and Creole Rock in the Orient Bay reserve, and steady trade winds for kitesurfing.

This is where Saint-Martin pulls clearly ahead. Anguilla's quiet beaches are a short ferry ride from Marigot, St Barths and Gustavia harbour are a longer crossing, and Saba and Sint Eustatius make a full day out. Philipsburg's Front Street and the low-flying planes at Maho Beach fill an easy half-day without leaving the island.

St Croix lies on its own, about 60km south of the other Virgin Islands. Getting to St Thomas or St John's beaches means a seaplane or a long boat crossing, which makes it a costly full day.

Saint-Martin has a slight edge with children. Le Galion's shallow, reef-protected bay and the short boat ride to Pinel are about as gentle as Caribbean swimming gets. Add a treetop zipline park in the hills and the planes at Maho, which older children enjoy.

St Croix has calm water at Rainbow Beach and an easy first snorkel at Buck Island, and American families need no passports. Neither island has a zoo, aquarium or theme park, so on both the days revolve around the beach and a pool at the villa.

Getting around is about equally awkward on both, and on both you will want a hire car. On St Croix the drive from one town to the other takes about forty minutes. You drive on the left, the roads range from good highway to potholed lanes, and the climb to the north shore is steep.

Saint-Martin's problem is traffic rather than road surfaces. It builds up around Marigot and the lagoon bridges, though minibuses link the towns and water taxis run out to Pinel and Tintamarre. The unmarked border means you hardly notice when you have crossed onto the Dutch side.

Saint-Martin gives shoppers more choice. Marigot's waterfront market has spices, rum and fabrics, with French boutiques and perfume in the streets behind. Over the border, Philipsburg's Front Street is lined with duty-free jewellery, watch and electronics shops, and guavaberry liqueur is the souvenir with the most local character.

St Croix's shopping is limited to the arcaded streets of Christiansted. The thing to buy there is the Crucian hook bracelet, made by local jewellers, along with Caribbean art and hot sauce.

Neither island is cheap, and for a budget traveller there is little between them. On St Croix almost everything is shipped in, so meals and groceries cost more than on the American mainland. It is still kinder to the wallet than the other Virgin Islands, and its roadside food stands and small guesthouses in Christiansted help.

On Saint-Martin, restaurant meals cost French prices or more, and boat trips to the islets and neighbouring islands push the bill up. The lolos and supermarket picnics are the ways to save, and rates fall noticeably outside the winter season.

St Croix has a folk music of its own to look out for. Quelbe scratch bands play on gourds, banjo and flute, and mocko jumbie stilt-walkers dance alongside them, best seen at the Crucian Christmas Festival. Outside the festivals there is a small performing arts centre, and open-air jazz on the Frederiksted waterfront.

Saint-Martin has no theatre or concert hall at all. Its music is steel pan, zouk and soca at beach bars and on busy Grand Case evenings, and it peaks with the calypso and soca competitions of Carnival.

For relaxing, the two are much the same. Neither has a spa tradition, both have resort spas and a little yoga, and both work best simply as places to slow down. On St Croix the quiet comes from early evenings, with the West End and the villas in the east-end hills the calmest places to stay.

On Saint-Martin, look for a villa above Anse Marcel or a cove on the west coast, which keeps you away from the traffic and cruise-day crowds of Marigot.