Marco Island or Palm Beach?

Both are excellent beach destinations, but the beaches are different. Marco Island has one continuous, wide crescent of fine pale sand on the Gulf, with flat, shallow water, room for long walks and shelling at low tide, and the sandbar and tidal lagoon at Tigertail. The undeveloped shore of Keewaydin Island is a short boat ride away.

Palm Beach wins on the water itself: clear, blue-green Atlantic sea kept warm by the Gulf Stream, with reefs close offshore. The sand on the island is more limited. Public beaches are mainly the Municipal Beach and Phipps Ocean Park, and much of the shore sits behind seawalls or narrows at high tide, so for wider beaches you drive to Singer Island, Jupiter or Delray.

Palm Beach eats better, mostly thanks to West Palm Beach across the bridge. Its Cuban bakeries, Caribbean takeaways, waterfront green market and casual places around Clematis Street and Northwood add range to the formal French and Italian dining rooms on the island.

Marco Island sticks to Gulf seafood with a water view, from resort dining rooms to the dockside fish shacks of Goodland. It is pleasant but narrow, and for an ambitious dinner you drive to Naples.

There is a real gap here. Palm Beach is a Gilded Age resort with its history intact: Flagler's marble mansion at Whitehall, Mizner's tiled vias and Bethesda-by-the-Sea, the ocean-front estates along South Ocean Boulevard and the Norton Museum's collection across the lagoon. That is enough to fill two or three days.

Marco Island was built mostly from the 1960s on. Its one real cultural stop is the historical museum, which tells the story of the Calusa people and the carved wooden figures found on the island, so anyone who wants galleries has to go to Naples.

Neither place has much nightlife, but Palm Beach at least has somewhere to go. The island is asleep by eleven, but Clematis Street in West Palm Beach has bars, rooftop terraces and a couple of dance spots that fill with a younger crowd at weekends, and there are cocktail bars around Rosemary Square.

On Marco Island the evening is a sunset drink on a waterfront deck and then dinner. Its liveliest moment is the dockside bars in Goodland on winter weekend afternoons, and there are no clubs at all.

Marco Island is the stronger base for nature on land and in the estuaries. Mangrove keys and tidal channels start at the island's edge, Rookery Bay protects the estuaries just to the north, and Everglades National Park, Big Cypress and the cypress swamp boardwalks of Fakahatchee Strand are all within an hour.

Palm Beach's strength is under the sea. Reefs lie along the Gulf Stream, and the shallow dive site under the Blue Heron Bridge is famous for octopus and seahorses. On land there is the shaded Lake Trail and the Loxahatchee refuge, which is pleasant but a smaller taste of the Everglades.

Palm Beach has the better choice of day trips, mainly because Miami is about an hour away by fast train, with South Beach, Little Havana and Wynwood. Fort Lauderdale, Delray Beach and the Jupiter lighthouse are easy too, although many of the resort towns along this coast are alike.

From Marco Island, the outings are Naples, the old trading post at Chokoloskee and the Edison and Ford Winter Estates in Fort Myers. Miami is a long day across the Tamiami Trail, so the best excursions here are usually into the swamps rather than to towns.

Both work well for families, in different ways. Marco Island's appeal is the beach itself: soft sand, a calm, shallow Gulf, wading at Tigertail and resort children's programmes. Purpose-built attractions are half an hour away in Naples.

Palm Beach's own island feels made for adults, with formal restaurants and boutiques. The things children enjoy are nearby, though: the zoo, the science centre and aquarium, winter manatees at Manatee Lagoon and a drive-through safari park, as well as Peanut Island's sheltered lagoon for small swimmers.

You will want a car in both, but Palm Beach needs it less. Its core around Worth Avenue is easy to walk, the Lake Trail makes cycling simple, downtown West Palm Beach has a free trolley loop, and the fast train reaches Fort Lauderdale and Miami without any driving.

On Marco Island the cycle paths are handy for getting between beach, shops and restaurants, but everything beyond the island assumes a car. The bus link to Naples is limited and the airport is about three quarters of an hour away by road.

Palm Beach is the shopping destination of the two. Worth Avenue has the major luxury houses and jewellers among Mizner's courtyards, the consignment shops sell designer pieces from wealthy local wardrobes, and Antique Row is a draw for anyone furnishing a home.

On Marco Island, shopping means a few plazas selling resort wear, shells and coastal décor. Its nearest equivalent to Worth Avenue is Fifth Avenue South in Naples, half an hour's drive away.

Neither is cheap, but Marco Island is the easier on the wallet. Weekly condo rentals with kitchens help families and groups keep costs down, and summer room rates fall well below winter levels, although you still have to budget for a hire car.

Palm Beach is among the most expensive resort towns in the country, with high prices for rooms, dinners and even beach parking. The usual ways to save are to stay in West Palm Beach and drive over, and to make the most of free things like the beaches and the Lake Trail.

Palm Beach has a real winter programme. The Kravis Center hosts touring musicals, ballet and Palm Beach Opera's short season, Palm Beach Dramaworks puts on serious plays, and the Society of the Four Arts holds chamber concerts on the island.

Marco Island has a community theatre and guitarists in resort bars during the season, and its residents drive to Naples for the philharmonic. In both places the calendar thins out from late spring.

Marco Island offers rest mainly through its pace, while Palm Beach backs the same calm with bigger, better-equipped resort spas. On Marco the beachfront spas look out over the Gulf, the island's plazas have day spas and yoga classes, and the days are so unhurried that a week of doing very little takes no planning at all.

Palm Beach is the stronger choice if the spa is the reason for the trip. Its oceanfront resorts have large, polished spas with long treatment menus, salt-water pools and fitness programmes. Beach yoga, early swims in the warm Atlantic and quiet walks by the lagoon fill the rest of the day. Neither has public baths or a bathing tradition, so in both a wellness stay is built around a resort spa.