Hilton Head or Sanibel?

Both islands are beach places first, and on sand and swimming they are well matched. Hilton Head's Atlantic shore is a long sweep of firm sand, wide enough to cycle along at low tide, with mild surf and a choice between busy Coligny and quieter Driessen or Folly Field.

Sanibel's Gulf beaches are calmer still, shallow and almost waveless, and their draw is shelling, with people combing the tideline at Bowman's Beach and Lighthouse Beach for whelks and the rare junonia. On both islands the water is greenish rather than clear blue, and each has its occasional nuisance, jellyfish on the Carolina side and red tide in Florida.

Neither island is a food destination, but you will eat better on Hilton Head. Its Lowcountry cooking has more character, with she-crab soup, shrimp and grits, Lowcountry boils, oyster roasts in the cooler months and May River oysters from around Bluffton, whose old town adds a few more local kitchens.

Sanibel keeps to a shorter menu of grouper sandwiches, fried shrimp and stone crab claws in season, served at porch restaurants along Periwinkle Way. It is pleasant enough, but many menus repeat one another, and for variety people drive over the causeway to Fort Myers or down to Naples.

Both islands are thin on sights, and what differs is the subject. Hilton Head's history is the Gullah story, told at Mitchelville Freedom Park, a small Gullah museum and old family neighbourhoods, with plantation ruins and a Civil War fort as short stops.

Sanibel's sights belong to the island itself: the Bailey-Matthews National Shell Museum, the iron lighthouse of 1884 and a village of pioneer cottages, all easily seen in a morning.

Both islands go to bed early, but Hilton Head has a little more going on after dinner. Around Coligny and the marinas, waterfront decks with cover bands fill on summer nights, and a couple of bars stay open late.

On Sanibel the evening is a sunset and then dinner, perhaps with a guitarist in a Captiva restaurant bar in winter. Anything later means driving to Fort Myers Beach.

The two are evenly matched and similar in shape: flat land, warm water and wildlife rather than views. On Hilton Head that means salt marsh, with kayak trips through spartina creeks, dolphins feeding in Calibogue Sound, live oaks draped in Spanish moss and over 60 miles of paved paths.

Sanibel is the stronger choice for birdwatching. In winter the mangroves of the Ding Darling refuge draw roseate spoonbills and white pelicans, Tarpon Bay has mangrove tunnels to paddle, and manatees appear now and then. On both islands, summer heat pushes outings into the morning.

Hilton Head is far better placed for days away. Savannah's oak-shaded squares and historic district are under an hour away, Beaufort's antebellum port and St Helena Island are close, and a ferry reaches Daufuskie Island, which has no bridge to the mainland. Charleston makes a long but worthwhile day.

From Sanibel the outings are gentler. Captiva is next door, Fort Myers has the Edison and Ford Winter Estates and Naples has a polished old town. The boat trips to Cabbage Key, Cayo Costa and Boca Grande are the most memorable, but none of them has the pull of Savannah.

Hilton Head was largely laid out around the family beach trip. It has wide sand with gentle surf and bike paths that keep children away from traffic. There are also dolphin cruises, crabbing off the docks, mini golf, the butterfly house and summer evenings by the Harbour Town playground. Villas with pools and kitchens suit larger groups, though there is no theme park or aquarium.

Sanibel works best with younger children, who will happily hunt for shells in the shallow Gulf, watch alligators in the refuge or explore the touch tanks at the shell museum. Nothing on the island is built purely for entertainment, so teenagers are likely to run out of things to do sooner here.

Neither is easy without a car, and on getting around the two are broadly level. Hilton Head is reached from Savannah's airport and relies on one main road that clogs on summer weekends, and gated communities such as Sea Pines have entry checks. Its long path network and the hard sand at low tide make the bike the everyday way to get about.

Sanibel is smaller and reached by a causeway from Fort Myers. Its traffic peaks in winter along Periwinkle Way, when beach car parks also fill early. Here too the shared paths make cycling the pleasant way between beach, refuge and shops.

The open-air villages at Coligny, Shelter Cove and Harbour Town give Hilton Head a few hours of resort-wear boutiques, galleries and golf shops. The Bluffton outlets just over the bridge are the rainy-day standby, and Gullah sweetgrass baskets make a souvenir with real roots.

Sanibel's plazas along Periwinkle Way and in Captiva village are smaller, with shell shops, beachwear and coastal art. That makes a pleasant hour of browsing rather than an outing, and anything more means the malls on the mainland.

Hilton Head leaves more room to save. Spring and autumn cost noticeably less than the summer peak, a shared rental house with a kitchen spreads the bill, and Bluffton just inland has cheaper beds. Golf, bike hire and boat trips still add up.

Sanibel has no budget hotels at all, and its few cottages and condos book out at high rates from January to April. You will need a car on top. Fort Myers is the fallback for a cheaper bed, and on both islands the beaches and paths cost little.

Hilton Head has a real, if small, arts calendar. The Arts Center of Coastal Carolina puts on professional theatre and Broadway-style musicals, a symphony orchestra plays in winter, and there is a jazz festival, a Gullah celebration and free summer concerts at Harbour Town.

On Sanibel the arts are community-scale, with chamber concerts and amateur theatre in the winter season. Anyone after a touring show drives to the hall in Fort Myers.

For rest the two are level, and both offer it in the same way, through slow days rather than any spa or bathing tradition. Hilton Head is calmest out of season, with beach walks and evenings by the marsh, and has resort spas, including a grand riverside one near Bluffton.

Sanibel's calm comes from its low skyline, slow roads and days set by the tides and the sunset, and its evenings are quieter still. Resort spas on Sanibel and Captiva and a few yoga studios cover the rest.