Martinique or St Barts?

Both islands have excellent beaches, so the difference is in the kind of beach and how you reach it. Martinique's good swimming is on the Caribbean side and around the southern tip, so where you stay matters. Grande Anse des Salines is the palm-lined classic, Anse Noire and Anse Dufour put black and gold sand side by side, and turtles feed close to shore off Les Anses-d'Arlet. The Atlantic coast is mostly too rough for swimming, apart from the shallow sandbanks off Le François.

St Barts packs a surprising range into a few minutes' drive. Saline and Gouverneur are wild and unshaded, with surf on some days. Grand Cul-de-Sac has a calm lagoon behind its reef, and Colombier can only be reached on foot or by boat. At St Jean the small planes land low over the swimmers. Martinique's coves fill with local families at weekends, while St Barts' beaches are rarely busy.

Martinique eats better and more widely. Its Creole cooking runs from colombo and blaff to grilled conch at beach shacks and weekend roadside stalls. The covered market in Fort-de-France is full of spices and hot sauces, and the rhum agricole estates make the ti-punch part of every meal.

St Barts cooks French first. The long, rosé-fuelled lunches on the sand at St Jean or Saline and the polished dinners on hillside terraces are a pleasure, but there are few places, almost no cheap ones and no street food.

Martinique has far more to see. Saint-Pierre, destroyed by Mount Pelée in 1902, is a moving visit, with its ruined theatre and the prison cell of one of the very few survivors. Fort-de-France has the Schoelcher Library and its cast-iron cathedral, and the island also has Joséphine's birthplace and the Anse Cafard slavery memorial. Together they fill a few days of outings.

St Barts' century of Swedish rule left a clock tower, the small museum in the Wall House and old forts above Gustavia. A pleasant hour or two covers it.

St Barts has more going on after dark, though only in season. From Christmas into spring, beach lunches at St Jean turn into afternoon parties, and the evening moves on to the Gustavia harbour bars, a couple of late clubs and the decks of visiting yachts. New Year is its loudest week. By late summer many places shut.

Martinique's evenings are mostly a ti-punch and an early night. Its zouk and kompa clubs around Fort-de-France draw a local weekend crowd, but you need a car to reach them. Carnival is the time to go out there.

This is where Martinique pulls furthest ahead. Its UNESCO-listed volcanic north offers the climb up Mount Pelée, rainforest on the Pitons du Carbet and canyoning in the gorges. The Caravelle peninsula has mangrove and cliff trails. Offshore are the Diamond Rock dives, the wrecks off Saint-Pierre and the sailing harbour at Le Marin.

St Barts is dry, scrubby and small. The cliff path to Colombier is lovely and the marine reserve gives easy snorkelling with turtles, but beyond kitesurfing on the lagoon at Grand Cul-de-Sac a few days covers it.

Martinique has much more within reach. You can string its rum estates together like a wine route or drive to fishing villages such as Grand-Rivière. Fast ferries reach Dominica and St Lucia in about an hour and a half, which makes a whole other country a day trip.

From St Barts the one easy outing is the ferry to St Martin, for the busier streets of Marigot, Grand Case and Philipsburg. Anguilla and Saba need a charter.

Martinique has more to keep children busy. It has calm southern bays where children can snorkel with turtles, a small zoo in a ruined estate at Le Carbet, glass-bottom boats and French healthcare close at hand. The catch is the long, winding drives in the heat.

St Barts turns that around. It is very safe and every lagoon is minutes away, with Shell Beach and Petit Cul-de-Sac ideal for toddlers, but nothing is built for children and older ones may soon get bored.

On both islands you will need a hire car, but St Barts is easier day to day because nothing is far. Its hairpin roads are steep and narrow and parking in Gustavia is tight. Getting there also means a small plane or a ferry from St Martin.

On Martinique the distances add up, roads in the north twist through the hills and traffic jams build around Fort-de-France and Le Lamentin. The ferry across the bay to Les Trois-Îlets helps, and the easiest pattern is to stay in the south and drive north on chosen days.

St Barts is a real shopping destination for its size. The duty-free harbour streets of Gustavia hold luxury fashion, watch and jewellery boutiques, and St Jean sells resort wear.

Martinique's shopping is about what the island makes: aged rum bought at the estates, vanilla and hot sauces from the Fort-de-France market, madras cotton and basketry from craft villages.

Neither is cheap, but the gap is huge. Martinique charges French prices with an island premium, and you can soften them with a gîte, market food, beach snack bars, free hiking and estate rum tastings that cost little.

St Barts is among the most expensive places in the world. Villas, beach lunches and even the small-plane flight in are priced for the very wealthy, and cooking in the villa saves only a little.

Martinique has a living tradition worth seeking out in bèlè, the drum-and-dance evenings in village halls in the north and centre, where visitors often get pulled into the circle. Fort-de-France also has a national arts centre with a year-round programme.

On St Barts the highlight is the long-running January music festival in Gustavia's churches. The rest of the year it is mostly bands and DJs in the bars during the high season.

Neither island has a bathing tradition, so both rely on spas and a slow pace. St Barts does it with more polish: high-standard hotel spas, therapists and yoga teachers who come to the villa, no high-rises and a very quiet spring. The exception is the week around New Year.

Martinique's resort spas around Les Trois-Îlets and Sainte-Anne are simpler, though its warm volcanic springs in the northern forest add a dip you won't find on St Barts. The slow southern days are restful, as long as the driving is kept to a minimum.