Fort Lauderdale or Key West?

This is Fort Lauderdale's strongest point. A broad, pale strip of sand runs for kilometres behind the A1A promenade, with lifeguards along it. Quieter stretches lie north towards Pompano, and Hollywood's Broadwalk to the south feels more local. You can swim straight out from the shore, and you can snorkel a reef from the beach at Lauderdale-by-the-Sea.

Key West's water is just as warm and often calmer, but the beaches are small. Smathers Beach is built on imported sand, and Fort Zachary Taylor has rocky coral rubble where water shoes help. Most time in the sea there is spent on boat trips, and a classic beach day means driving to Bahia Honda.

The two are much alike for eating out, but the food differs. Fort Lauderdale has more variety: Las Olas restaurant terraces, dockside fish shacks on the Intracoastal, and Jamaican, Haitian and Cuban cooking in the inland suburbs, with brunch as a local habit.

Key West's food is narrower but more its own. It means pink shrimp, conch fritters, Key lime pie and strong Cuban coffee from takeaway windows in Bahama Village and around the seaport.

Key West has more to see, and most of it is the town itself. Old Town's conch cottages, Victorian verandas and cigar-era houses make a long walk worth taking. Around them are the Hemingway Home, the Truman Little White House, Audubon House and a brick Civil War fort.

Fort Lauderdale's sights take about a day. The best is the eccentric Bonnet House estate, followed by the pioneer Stranahan House on the New River and the modern collection at the NSU Art Museum. You go there for the water, not for its history.

Key West makes more of its evenings. The night starts at sunset on Mallory Square and moves along Duval Street, a walkable run of open-sided bars, rooftop decks and old saloons that stay open into the small hours. The upper end of the street has a long-established gay scene.

Fort Lauderdale is more spread out and depends more on the day of the week. There are beach bars on A1A, late bars on Himmarshee Street and wine terraces on Las Olas. Its standout is Wilton Manors, a nationally known gay neighbourhood. Neither place has much club culture.

Both are flat, and in both the outdoors means water, but the settings differ. In Fort Lauderdale you paddle the canals and the Intracoastal past waterfront mansions, dive on sunken wrecks close to shore, and drive under an hour to the edge of the Everglades to see alligators and sawgrass marsh.

Key West has the Florida Reef a few kilometres out, mangrove flats for kayaking and fly-fishing for tarpon and bonefish, and the remote Dry Tortugas for clear water and birdwatching.

Fort Lauderdale is far better placed. Miami's Art Deco district, Wynwood and Little Havana are under an hour away by car or fast train, and Palm Beach's Flagler Museum is an easy drive north. Key Largo is just within reach for a long day.

Key West sits at the end of a single road, so there is much less within reach. The Dry Tortugas ferry to Fort Jefferson makes one memorable day out. Otherwise there is Marathon's turtle hospital and the drive over the Seven Mile Bridge. Miami is too far to go there and back in a day.

Fort Lauderdale is the easier place for children. It has a gentle, lifeguarded beach with showers and parks, the Museum of Discovery and Science with its aquarium, a butterfly garden and aviary, and Everglades airboat rides. The drawbacks are the summer storms and needing a car for most outings.

Key West can still please children who like the water, with glass-bottom boats, the calm shallows at Fort Zachary Taylor and the six-toed Hemingway cats. But the island's bar culture and the very adult Fantasy Fest make it a harder fit.

Key West is far easier without a car. Old Town is compact and flat, and nearly everything lies within a short walk or bike ride of Duval Street. Driving in the narrow centre is more trouble than it is worth, though you need wheels to reach Bahia Honda or Big Pine.

Fort Lauderdale is built for driving. The beach, Las Olas and downtown are walkable and linked by water taxis and free trolleys. Beyond that area, buses are slow, and most visitors hire a car. The trains to Miami and the Palm Beaches are useful for day trips.

Fort Lauderdale offers more shopping. Las Olas Boulevard is good for an unhurried afternoon of boutiques, swimwear and galleries, and the huge outlet mall out in Sunrise attracts serious bargain hunters.

Key West's shopping is mostly T-shirts and Key lime everything. Its better finds are small: tropical art in the Old Town galleries, hand-rolled cigars and sponges from the harbour shops.

Neither is cheap, but Key West costs noticeably more. Limited land and strong demand push room rates above most American cities, and boat trips, diving and the Dry Tortugas ferry add up. It does save money in one way: you can walk or cycle everywhere, so you don't need a car.

In Fort Lauderdale you need a car and pay for parking, but there are more ways to cut the cost of a room. Self-catering apartments and older motels a few blocks back from the beach help. In both places the hot, stormy summer is the cheapest time to go.

The two are close here, but the kind of evening differs. Fort Lauderdale has the bigger stage. The Broward Center on the New River brings touring Broadway shows, ballet and concerts, and the Parker Playhouse adds to the programme.

Key West's performances are smaller and more its own. There are street performers at sunset on Mallory Square, nightly drag cabaret, songwriters in the Duval bars, the Tennessee Williams Theatre, and a symphony that plays in winter only.

Neither has any bathing culture, so in both places relaxing comes from the slow pace rather than the spas. In Fort Lauderdale that means sunrise yoga on the sand and long walks along the promenade. In Key West it means guesthouses built around small pools and gardens on quiet Old Town lanes, as long as you stay well away from the noise of Duval.