Turks and Caicos or US Virgin Islands?

Both are first-rate, but they offer different kinds of beach. Turks and Caicos centres on one great sweep: Grace Bay's long white shore, kept calm by the reef offshore. The glassy south-side bays of Providenciales are good for wading, and boats run out to empty cays such as Pine Cay. The land behind the sand is low and flat.

The US Virgin Islands spread their best beaches across three islands. On St John, national park bays such as Trunk, Cinnamon and Maho sit below green hills. On St Thomas, Magens Bay is a long, sheltered curve, while Coki Point and Sapphire Beach let you snorkel straight from the sand. The north shores can pick up swell in winter, and on those days the south-facing coves are calmer for swimming.

The US Virgin Islands give you more to eat locally. There is a full West Indian kitchen of kallaloo, fungi, goat stew and pates at roadside stands and church food fairs, and St Croix adds rum distilleries and the best home cooking in Frederiksted and Christiansted.

Turks and Caicos has a narrower local repertoire that is almost all seafood. You get conch in every form and spiny lobster in season, eaten at its best at a fish fry or conch shack along the Blue Hills shore. Away from those, meals are international dishes at Grace Bay resorts, made with imported produce.

Heritage is a real if modest draw in the US Virgin Islands, and barely one in Turks and Caicos. Nearly two centuries of Danish rule left Christiansted's yellow fort and arcaded streets and Charlotte Amalie's red Fort Christian, 99 Steps and sand-floored synagogue. The sugar estates at Annaberg and Whim tell the plantation story.

In Turks and Caicos, the history worth seeing is mostly a flight away on Grand Turk. There you will find the Bermudian-style houses of Cockburn Town, the National Museum with its early Molasses Reef wreck, and the salt ponds that Salt Cay keeps almost untouched. On Providenciales there is little more than the ruins of Cheshire Hall.

Neither place has clubs, but the US Virgin Islands at least have streets that fill up. Red Hook and Cruz Bay draw charter-boat sailors and crowds that spill out of the open-air bars, Christiansted's boardwalk is busy after dark, and carnival on St Thomas and the Crucian Christmas festival run late for weeks.

Turks and Caicos stops at a rum punch on Grace Bay. You get sunset drinks at beach bars and resort lounges, sometimes a local band, and quiet well before late. The outer islands are quieter still.

Both are strong outdoors, but in different places. The best of Turks and Caicos is in the water and on the flats. There is reef snorkelling off the Caicos Islands, a dramatic wall dive close to shore off Grand Turk and Salt Cay, humpback whales from about January to April, kiteboarding at Long Bay and bonefishing on the Caicos Bank. On land it is low scrub and salt ponds, with flamingos on North Caicos and the caves on Middle Caicos.

The US Virgin Islands add proper hills. St John is mostly national park, with dry forest and the Reef Bay trail past petroglyphs down to the sea. The sheltered water is ideal for day sails, and Salt River Bay on St Croix glows with bioluminescence on dark nights.

Island-hopping is far easier from the US Virgin Islands. St John is a short ferry ride from St Thomas, Water Island is minutes from Charlotte Amalie, and with a passport you can reach Jost Van Dyke, Tortola and Virgin Gorda in the British Virgin Islands in about an hour.

From Providenciales, the options are fewer and take more planning. A ferry and a drive get you to the sleepy settlements of North and Middle Caicos. The most rewarding outing, Grand Turk and Salt Cay, depends on small inter-island flights.

With toddlers, Turks and Caicos is the easier of the two. Grace Bay shelves gently, the lagoons at Taylor Bay and Sapodilla Bay are shallow enough for wading, and the big family resorts with kids' clubs sit on flat, easy ground. Older children can snorkel straight from the shore at Smith's Reef.

The US Virgin Islands give children a little more to do. Coki Point has touch pools and an underwater observatory, and turtles feed in shallow water at Maho Bay. The downside is steep, winding roads and hillside resorts that tire small legs. American families can also travel without a passport.

The US Virgin Islands are easier to move around, though not easy. On St Thomas and St John, open-sided safari taxis run fixed routes between town and beach, and frequent ferries link Red Hook and Cruz Bay. The roads are narrow and steep, and a jeep helps on St John.

Turks and Caicos has no useful public transport, so you rely on taxis or a hire car to reach Chalk Sound or the south-side bays. The central stretch of Grace Bay can be walked. Going further means a ferry to North Caicos or a small plane to Grand Turk, which is why many visitors stay put. Traffic keeps to the left on both.

Charlotte Amalie gives the US Virgin Islands a real shopping street. Its old Danish warehouses along Main Street are full of duty-free jewellers and watch dealers, even if the stock repeats from shop to shop. Cruz Bay and the Christiansted studios add island-made pottery, art and the St Croix hook bracelet.

Turks and Caicos has only a few small open-air plazas on Grace Bay selling resort wear and duty-free watches. The best things to take home are woven palm-straw baskets and hats from North and Middle Caicos and sea salt from the old salt islands.

Both are expensive, but Turks and Caicos is the harder on the wallet. Grace Bay is mostly upmarket resorts and condo hotels, nearly all food is imported, and short taxi rides, diving and inter-island flights cost a lot. Sharing a self-catering villa and eating at conch shacks are the main ways to save.

The US Virgin Islands give you more room to economise. St Croix and St John's guesthouses and campgrounds cost less than the east end of St Thomas, and the park beaches and trails are free or nearly so. Summer and autumn rates are lower, though that is hurricane season.

Neither destination has a performing arts programme to plan around, but the US Virgin Islands have more local tradition to catch. Quelbe scratch bands, steel pan, calypso and the stilt-walking mocko jumbies turn up at festivals and cultural nights, and touring concerts play the open-air amphitheatre at the University of the Virgin Islands.

In Turks and Caicos, the local sound is ripsaw music, played on a carpenter's saw at fish fries and resort evenings. The Maskanoo street parade at Christmas is the one big occasion.

Neither has a bathing tradition, and on both islands the spa offer belongs to the resorts. Turks and Caicos has the more complete retreats: private island resorts on the cays north of Providenciales built around yoga, treatments and healthy food, with full open-air spas along Grace Bay.

The US Virgin Islands rely more on pace than on pampering. A hammock on St John or St Croix's quiet east end, well away from the cruise traffic around Charlotte Amalie, is the closest thing to a rest cure.