Key West or Marco Island?

Marco Island is the true beach destination of the two. Its western shore is a continuous sweep of pale, fine sand with calm, shallow water, Tigertail adds a lagoon and sandbar for wading, and Keewaydin's undeveloped shore is a short boat ride away.

Key West's appeal is the water rather than the sand. Smathers is imported sand, Fort Zachary Taylor has clear water but a coral-rubble shore, and seagrass and seaweed limit long swims. In winter, though, its sea stays a little warmer than the Gulf off Marco.

Both eat mostly from the sea, but Key West has more character at the table. Cuban influence gives it café con leche and Cuban sandwiches from takeaway windows, and the fish shacks of the Historic Seaport and Bahama Village sit alongside a few more ambitious Old Town dining rooms.

Marco Island offers grouper, shrimp and stone crab with a water view, plus Goodland's dockside platters, but there is little beyond seafood, steak and Italian. For a special dinner most visitors drive to Naples.

Key West has a real historic town to explore, one of the largest districts of old wooden buildings in the United States, with the Hemingway Home, the Truman Little White House, the lighthouse and the shipwreck collections telling a story of wreckers, writers and presidents.

Marco Island is a resort community built from the 1960s, and its main cultural stop is the historical museum on the Calusa people and their famous carved wooden figures. Anyone wanting more than an afternoon of history should choose Key West.

Key West is the island for a night out, by a wide margin. Evenings begin with the crowd watching the sunset on Mallory Square and then drift inland to Duval Street, where people wander from bar to bar with a drink in hand. The crowd is a mix of cruise passengers, fishermen, stag groups and a long-standing gay scene at the upper end of the street. Expect shorts, cover bands and a rowdy, good-humoured mood rather than cocktail craft or dancing. Winter and Fantasy Fest in late October are the liveliest times.

Marco Island goes to bed early. For most of its visitors, largely retirees and families, a night out means a drink on a waterfront deck at sunset, dinner and perhaps a nightcap in a resort lounge. Goodland's dockside bars are busiest on winter weekend afternoons rather than after dark. The island has no clubs, and Naples, half an hour away, is only a little livelier.

Marco Island has the wider natural setting. The mangrove maze of the Ten Thousand Islands, manatees and dolphins, Rookery Bay and, within an hour's drive, Everglades National Park, Big Cypress and the Fakahatchee Strand give paddlers, anglers and birdwatchers plenty to do on water and land.

Key West's outdoors is almost entirely at sea, but what it has is distinctive: the Florida Reef for snorkelling and diving, backcountry flats for tarpon and bonefish, and the remote Dry Tortugas. For coral and clear water it is the stronger choice.

Marco Island has more within easy reach. Naples is half an hour away, and Everglades City with Chokoloskee, the Edison and Ford Winter Estates in Fort Myers, and the islands of Sanibel and Captiva all make comfortable outings.

Key West sits at the end of a long road, so options are fewer. The ferry to Fort Jefferson in the Dry Tortugas is a memorable day, and the drive over the Seven Mile Bridge to Marathon or Islamorada is pleasant, but Miami and the Everglades are too far for a day out.

Marco Island is easier with young children. Soft sand, calm shallows, the Tigertail lagoon and resort pools with children's programmes keep days simple, and Naples' zoo and children's museum are half an hour away.

Key West has more small attractions in town, such as the aquarium, the butterfly conservatory and the Hemingway cats, plus glass-bottom boat trips to the reef. But Duval Street's early drinking and adult festivals mean families need to choose their base and their hours with care.

Key West is much easier without a car. Old Town is compact and flat, most sights and the harbour lie a short walk from Duval Street, and bikes, electric carts and scooters are the local way to get about, even if buses are thin.

Marco Island has cycle paths along its main roads, but anything beyond the beach and nearby plazas, including Naples, the Everglades and the airport, assumes you have a hire car.

Neither island is a shopping trip, but the browsing differs. Key West's Old Town galleries, hand-rolled cigars and harbour sponge shops have a local story behind them, while Marco Island's plazas offer resort wear and shell décor, with Naples' Fifth Avenue South boutiques and department stores half an hour's drive away.

Both are expensive, and neither suits a tight budget. Key West's scarce land pushes up rooms, and boat trips and the Dry Tortugas ferry add up, though walking everywhere and Cuban takeaway windows help.

On Marco Island, winter resort rates and pricey dining are matched by the cost of a hire car, while weekly condo rentals with kitchens ease things for families. On both, the hot summer brings the lowest room rates.

Key West offers more to watch. Bands and singer-songwriters play the Duval bars nightly, drag cabaret is a long local tradition, and the Mallory Square sunset brings out jugglers and tightrope walkers, with the Tennessee Williams Theatre and a winter symphony for something more formal.

Marco Island has a community theatre and winter guitarists in resort bars, and for an orchestra or touring show you drive to the performing arts centre in Naples.

Marco Island is the calmer place to unwind. The whole island is quiet, and the big beachfront resorts have full spas with pools facing the Gulf.

Key West can be restful in the guesthouses and gardens of Old Town's back lanes, but the party on Duval Street is never far off, especially at weekends and during festivals. Neither has any bathing or thermal tradition.