St Barts or St Croix?

Both islands have excellent beaches with the same warm, clear water, so the choice is about the kind of beach. St Barts packs a lot of variety into a tiny space: wild, shadeless Saline and Gouverneur, the reef-sheltered lagoons at Grand Cul-de-Sac, walk-in-only Colombier and St Jean with planes landing overhead. Every one of them is a few minutes' drive from your villa.

St Croix's beaches are more spread out and a little longer. Sandy Point and Rainbow Beach on the west end face the sunset, Cane Bay lets you snorkel straight off the beach, and Buck Island's white sand is a boat ride away. Expect more driving between them and fewer of St Barts' small, polished coves.

St Barts eats better, if you are happy with one style of cooking. Fresh croissants from the boulangeries, French cheese in the supermarkets, long lunches on the sand at St Jean and refined French cooking on hillside terraces add up to a consistently high standard, although nearly all of it sits at the same expensive level.

St Croix is less polished but more of a place of its own. The best meals are Crucian: johnny cakes, kallaloo, goat stew and roti from roadside stands, plus rum distilleries near Frederiksted. The restaurants in Christiansted lean towards American food and are narrower in range.

St Croix has far more to see. Christiansted's Danish waterfront is a national historic site, Frederiksted's fort is where emancipation was proclaimed, and the Whim estate and ruined sugar mills tell the harder story of the plantations. You could fill several half-days with it.

St Barts' Swedish past left a clock tower, the small museum in the Wall House, ruined forts and the village of Corossol. It makes a pleasant morning in Gustavia and little more.

St Barts has the bigger scene, though it is a narrow and seasonal one. From Christmas into spring, beach lunches at St Jean turn into afternoon parties, the evening moves to the harbour bars and a couple of late clubs in Gustavia, and New Year brings the superyachts. Late summer is almost silent.

St Croix's nights are relaxed and early. Rum drinks in Christiansted's courtyards and on the boardwalk, sunset beach bars, and late nights only during the Christmas festival season. There is nothing like a club scene.

St Croix has more to offer outdoors, above all underwater. The marked trail at Buck Island Reef, the wall at Cane Bay and the night dive under the Frederiksted pier are serious draws. On land it adds the trails to Point Udall, a patch of rainforest in the north-west, bioluminescent kayaking at Salt River Bay and nesting leatherbacks at Sandy Point.

St Barts is mostly about the water too: snorkelling with turtles in the marine reserve and kitesurfing on the Grand Cul-de-Sac lagoon. The land is limited to a cliff path to Colombier and a few short viewpoint walks.

On both islands you will spend nearly all your time on the island. From St Barts the one realistic outing is the hour's ferry to St Martin, for Marigot, Grand Case and Philipsburg.

St Croix's trips are longer and pricier: a seaplane or a slow boat to St Thomas or to the beaches of St John. Most visitors simply travel between Christiansted and Frederiksted instead.

Both islands work for families who want water and little else, and neither has an aquarium or anything else built for children. St Barts is safer-feeling and tinier, with calm, shallow water at the Cul-de-Sac lagoons and Shell Beach, but its tone is set by adults.

St Croix gives children a little more to do: a first snorkel at Buck Island, turtles, tide pools and a fort to clamber over. American families also skip passports. The trade-off is longer drives and rough paths down to some coves.

Either way you will need a hire car, with no useful buses on either island. St Barts is only a few kilometres across, so every drive is short, but the roads are steep, narrow and full of hairpins, and arrival means a small plane onto a famously short airstrip or a ferry.

St Croix is bigger, about forty minutes from one town to the other, with driving on the left and roads that run from highway to potholed lanes. Christiansted is the more rewarding town to explore on foot.

St Barts is the place to shop. Duty-free status brings a dense cluster of luxury fashion, watch and jewellery boutiques to the Gustavia harbour, with resort wear in St Jean and straw work from Corossol.

St Croix keeps it small and local: the Crucian hook bracelet from Christiansted's jewellers, Caribbean art galleries, rum and hot sauce. Serious shoppers take the seaplane to St Thomas.

Neither is cheap, but St Croix costs noticeably less. Its guesthouses in Christiansted, roadside food stands and free beaches give you ways to keep the daily bill down, even though shipped-in goods push up restaurant and supermarket costs.

St Barts is in a different league, among the costliest vacations anywhere, from the villa and the beach lunch to the small-plane flight in. Cooking in your villa is the only real saving.

Neither island is worth a trip for performances, and St Croix has a little more. Its own folk traditions, quelbe scratch bands and stilt-walking mocko jumbies, come out at the Crucian Christmas Festival and the winter agricultural fair, and Frederiksted has waterfront jazz.

St Barts relies on its January music festival of classical music and opera in Gustavia's churches, plus carnival parades and bar bands in season.

St Barts is the more restful of the two. Its luxury hotel spas are of a high standard, therapists and yoga teachers come to your villa, and with no high-rises or casinos the days drift from beach to lunch to sunset, except during the noisy New Year week.

St Croix is calm too, with early evenings and quiet villas on the West End and the eastern hills. Its spa offer is thinner, though: a few resort spas and massage studios.