Marco Island or Sarasota?

Both have soft Gulf sand and calm, shallow water with no real surf, so the difference is in the layout and the feel. Marco Island's shore is one continuous crescent made for long walks and shelling. Tigertail has a lagoon and sandbar for wading, and Keewaydin Island's undeveloped beach is a short boat ride away. In winter its water also stays a little warmer.

Sarasota spreads its beaches across several keys, so you can change beach from day to day: Siesta Key's cool white quartz sand, Lido Key close to downtown, quieter Longboat Key, and shark teeth to hunt for at Venice. Red tide sometimes closes beaches there, so it pays to check conditions first.

Neither is a place to plan a trip around meals, and both rely on Gulf seafood: grouper sandwiches, stone crab claws in the cooler months, fish eaten by the water. On Marco Island the choice runs out soon after that. Goodland's dockside fish platters are the most characterful meal, and for anything more ambitious you drive to Naples, half an hour away.

Sarasota gives you more choice without leaving town. There are bistros and wine bars on Main Street and St Armands Circle, farmers' markets and brunch places, and the hearty Amish and Mennonite cooking and pie of Pinecraft.

The gap here is wide. Marco Island is a resort built from the 1960s onwards, and its one real stop is the historical museum, which covers the Calusa people, the carved wooden figures found on the island and its clam-cannery past.

Sarasota has the Ringling, worth a full day on its own for its Baroque paintings, the Venetian Gothic mansion on the bay and the circus museum. Add the mid-century modernist buildings of the Sarasota School and the 1920s streets of Burns Court and there is enough for several days, though neither town has an old quarter.

Neither suits a big night out, but Sarasota at least gives you a choice of where to have a drink. Marco Island goes quiet after dinner. Resort lounges and a few marina bars stay open for a while, and the liveliest moment is Goodland's dockside crowd on winter weekend afternoons.

In Sarasota, Main Street has wine bars, cocktail bars and pubs, and the open-air beach bars of Siesta Key Village keep going after sunset. For anything louder, Sarasota people head to Tampa or St Petersburg, while Marco Island has only restrained Naples.

Both are flat, humid and full of wildlife, but Marco Island is much closer to wild country. It sits at the edge of the Ten Thousand Islands, so mangrove channels, dolphins, manatees and some of Florida's best inshore fishing start from the dock. Everglades National Park, Big Cypress and the Fakahatchee Strand are all within an hour.

Sarasota's highlight is Myakka River State Park, with its prairies, canopy walkway and alligators. There are also mangrove tunnels off Lido Key and dolphins in the bay. It is easy, pleasant nature rather than wilderness. In both places the dry months from late autumn to April are the time to be outside.

From Marco Island the list is short and leans towards nature. Naples is half an hour away, Everglades City and Chokoloskee make a morning out, and Sanibel and Captiva lie beyond Fort Myers.

Sarasota has more towns within reach: St Petersburg and its Dalí Museum across the Sunshine Skyway, Ybor City in Tampa, Greek Tarpon Springs, and Anna Maria Island and Venice close by. The Edison and Ford Winter Estates at Fort Myers lie between the two and are about an hour from each.

Both suit small children for the same basic reason: calm, shallow water and soft sand. Marco Island keeps things simple, with shelling, wading in the Tigertail lagoon, dolphin-spotting boats and resort pools with children's programmes. The zoo and the children's museum are in Naples.

Sarasota has things to do in town as well as on the beach: Mote Marine's aquarium with sharks, sea turtles and manatees, and the giant circus model at the Ringling. Neither has a theme park nearby, and in both the summer heat makes midday outings hard work.

You will want a hire car in both. Marco Island is small and flat enough to cycle between the beach, shops and restaurants. Beyond that the only public transport is a limited bus to Naples, and the nearest major airport is about three quarters of an hour away.

Sarasota is a little easier. Downtown, St Armands Circle and Siesta Key Village are each pleasant on foot, a free trolley runs along Siesta Key, and the drives between keys, museums and parks are short. The price is winter traffic on the bridges to the keys.

Marco Island's shops fill a few small plazas selling resort wear, beach gear, shells and coastal décor. For proper boutiques and galleries, you drive half an hour to Fifth Avenue South and Third Street South in Naples.

Sarasota keeps more of its shopping in town. St Armands Circle is the place to browse galleries, jewellery and gifts, Main Street and Palm Avenue have independent boutiques, and a regional mall covers the chains. There is also a Saturday farmers' market downtown. Even so, few people choose either place for the shops.

Marco Island leaves you fewer ways to save than Sarasota. It has little apart from beachfront resort rooms and condos, its restaurants are priced for a well-off winter crowd and cheap food is scarce. That makes summer rates or a weekly condo with a kitchen the main ways to cut costs.

In Sarasota you can stay inland or on the mainland instead of on the keys, the public beaches are free and the state parks cost little to enter. Still, neither is cheap. January to April is the most expensive stretch in both, and a hire car adds to the bill wherever you stay.

This is one of the clearest differences between the two. Marco Island has a small community theatre and musicians playing in resort bars in winter. For the philharmonic or a touring show, you drive to Naples.

Sarasota has an opera company in a restored 1920s theatre, a ballet known for its Ashton repertoire, a full orchestra season, the Asolo Rep on the Ringling grounds and touring shows at the purple Van Wezel hall. In both places the season runs mainly from autumn to spring.

Marco Island is the quieter place to switch off. It is a low-key island where the big resort spas have pools facing the Gulf, and there are day spas and yoga classes in the plazas.

Sarasota has something Marco Island lacks: Warm Mineral Springs, about forty minutes south, a spring-fed pool that stays warm all year and has drawn bathers for generations. Closer in, there are spas on Longboat Key and Lido Key and the odd sunrise yoga class on the sand, but winter traffic on the keys can take some of the calm away.