Key West or St. Pete Beach?

Here St. Pete Beach is far ahead. One long, continuous strip of soft quartz sand runs the length of the island, with shallow Gulf water you can wade into. Pass-a-Grille is the relaxed southern end, and the untouched sands of Fort De Soto and Shell Key are nearby.

Key West's appeal is the water rather than the shore. The sea is warmer through the winter and calmed by the reef, but Smathers is imported sand, Fort Zachary Taylor is coral rubble, and a classic beach day means driving an hour to Bahia Honda.

Both places eat casually and mostly from the sea, and neither has much range beyond that. Key West has more of its own identity, thanks to Cuban sandwiches and café con leche from takeaway windows, conch fritters and the long-running argument over Key lime pie.

St. Pete Beach is grouper sandwiches and smoked fish spread on a deck at sunset, with plenty of chain restaurants along Gulf Boulevard. For more ambitious cooking, people drive over to St. Petersburg.

Key West has far more to see. Its Old Town of wooden conch cottages and Victorian mansions is a sight in its own right, and the Hemingway Home, the Truman Little White House and the shipwreck collections fill a couple of good days.

St. Pete Beach has the pink Don CeSar hotel, Pass-a-Grille's old cottages and the batteries at Fort De Soto. For serious museums such as the Dalí, you cross the bay to St. Petersburg.

Nights out are where the two differ most. Key West carries on past midnight: crowds move from Mallory Square to Duval Street's open-sided bars and rooftop decks, with a long-established gay scene at the upper end. The nights are loud and boozy rather than polished.

St. Pete Beach gathers at tiki decks for the sunset and goes quiet not long after. A bigger night means the half-hour drive to downtown St. Petersburg.

Both are flat places where you spend your outdoor time on the water, and neither has real hiking. Key West has the coral reef a few kilometres offshore for snorkelling and diving, backcountry flats for tarpon and bonefish, and the remote Dry Tortugas.

St. Pete Beach is gentler and closer to shore. It has kayak trails through the mangroves at Fort De Soto, dolphins from the boats, manatees in the bay in the cooler months, and roseate spoonbills for birdwatchers.

St. Pete Beach sits on the edge of a large metropolitan area. St. Petersburg is half an hour away, Tampa's Ybor City is under an hour, and the Greek sponge docks of Tarpon Springs and Sarasota's Ringling estate are an easy drive.

Key West is at the end of the road. Apart from the ferry to Fort Jefferson and a drive over the Seven Mile Bridge to Marathon, there is little to reach in a day.

St. Pete Beach is much easier with children. The water is shallow and calm, the sand is soft, and many Gulf Boulevard hotels have pools. Beyond the beach there are dolphin boats, shelling on Shell Key, and aquariums and a theme park within an hour.

Key West has a glass-bottom boat, a butterfly conservatory and the six-toed Hemingway cats. Still, the town's evenings revolve around drinking, and you will spend some effort keeping children away from Duval Street.

Key West is the easier place to do without a car. Old Town is compact and flat, everything lies within a walk or short bike ride of Duval Street, and a car is more of a burden than a help.

St. Pete Beach is a long, narrow strip with a beach trolley along Gulf Boulevard. Fort De Soto, St. Petersburg and every day trip need a hire car, because the buses to the mainland are slow.

Neither place is worth visiting for its shops, but Key West has more to browse. Its Old Town galleries sell tropical art, and there are hand-rolled cigars and sponge shops by the harbour. St. Pete Beach offers swimwear and a few boutiques on Corey Avenue, and serious shopping means a drive to Tampa.

Both are expensive, but Key West is the harder on a budget. Limited land pushes up the price of every room, and boat trips, diving and the Tortugas ferry add up quickly. You do save on transport, because you can walk or cycle everywhere.

St. Pete Beach is easier on the wallet, thanks to older motels a block back from the sand and beaches that cost only the parking. A hire car takes back some of that saving.

Key West puts on more of a show. Every evening, jugglers, musicians and trained-cat acts perform at Mallory Square. The island also has long-running drag cabaret, songwriters in the Duval bars, and plays at the Tennessee Williams Theatre in season.

At St. Pete Beach, live music means cover bands on beach decks. For the Florida Orchestra, touring musicals or opera, you drive to St. Petersburg or Tampa.

Both are good places to unwind, though neither has thermal baths or a bathing tradition, and spas mostly mean resort hotels. In Key West the calm is found in garden guesthouses and the quiet lanes of Old Town, with the bars never far away. St. Pete Beach has a slower pace, built on morning walks on the sand and long, empty afternoons around Pass-a-Grille.