Though the Keys don't have large beaches, they do have several fine parks and recreation areas for swimming. Most daytime activities center on the water, either under or on it. Snorkeling and diving the coral reefs is the leading activity, but the waters off Islamorada provide excellent opportunities for sport fishing.

On the Beach

If you want to take time out for a swim, head to Long Key State Recreation Area, an 849-acre park on Long Key, in the middle of the Florida Keys. With a shoreline punctuated by mangrove lagoons, shallow flats, and narrow beaches with gentle surf, this long and narrow park also features excellent salt and freshwater fishing, picnicking, boating, swimming, diving, and boardwalk nature trails that lead you through a tropical hammock to an observation tower and to the beach where you can wade or snorkel out onto the flats. The most intimate way to enjoy this area is to rent a canoe and follow the marked canoe trail through the tidal lagoons, with nothing more than the wading shore birds to keep you company.

Many consider the palm-fringed beaches fronting both the Atlantic Ocean and the Gulf of Mexico at the 276-acre Bahia Honda State Recreation Area, Florida's southernmost park, to be the best swimming beaches in the Keys. The park's northeast section circles a blue and green lagoon. Here, remnants of the undeveloped Keys remain. Rare birds like the roseate spoonbill fly through satinwood and silver palms while dwarf morning glories provide color along the nature trail that meanders along the shoreline and through a hammock. Plan to stop for a picnic and a swim, or perhaps to fish in the bay or the ocean. Birding is especially good here, with sightings of great white herons, roseate spoonbills, crowned pigeons, and giant ospreys, whose nests top telephone poles along the highway. You can also rent windsurfing equipment at the marina in the southern part of the park. (Open daily 8 A.M.–sunset, 305-872-2353)

On the Boat

In the Keys, the best points of departure for deep-sea fishing are Key Largo, Tavernier, Islamorada, Duck Key, Key Colony Beach, and Marathon. If you're an experienced angler, you'll delight in going after bonefish, a fish found nowhere else in North America and an elusive scrapper that anglers actually stalk. Even if you're not experienced, go out and try your hand at catching some world-class fish. Charters provide all tackle and bait, and special fly-fishing guides will help you if you're not a seasoned angler.

The waters of the Keys teem with tuna, marlin, wahoo, grouper, dolphinfish, and sailfish. All boats come with state-of-the-art fishing equipment. For a unique fishing trip, try fishing at night for swordfish. Other charters specialize in fishing for tarpon and shark in shallower waters. Here is a selection of charter companies:

• Bounty Hunter: Marathon, 305-743-2446

• Charters Unlimited: Key Largo, 305-451-9289

• Choice Backcountry Charters: Islamorada, 305-664-2972

• Two Conchs Charters: Marathon, 305-743-6253

• Vagabond Charters: Key Largo, 305-310-1962

• Yellowfin Charters: Islamorada, 305-664-5333

If you can get a group of six or more together, you can hire a party boat from:

• Gulf Lady: Islamorada, 305-664-2628

• Marathon Lady: Marathon, 305-743-5580

• Sailor's Choice: Key Largo, 305-451-1802

Under the Water

Divers and snorkelers find an underwater array of colorful fish darting among forty species of corals along the reef that parallels the Keys. Besides the reefs at the John Pennekamp Coral Reef State Park and the adjacent Key Largo Coral Reef National Marine Sanctuary off Key Largo, there are the Crocker and Alligator Reefs, just off Islamorada, both with almost vertical walls containing cracks and crevices that provide homes for crabs and shrimp that attract larger predators.

One of the most interesting sites in the Islamorada area is the San Pedro Underwater Archaeological Preserve, south of Indian Key. A hurricane drove the San Pedro, a 287-ton Spanish galleon that set sail from Havana in July 1733, onto the reefs. Today, it lies just 18 feet below the surface and is accessible as a scuba-dive or aboard a glass-bottom boat. You'll see the original anchors, concrete canon replicas, ballast, and bricks. If you dive to the site, you can follow an underwater nature trail to observe a variety of fish, corals, and conchs.

Around Marathon, you'll find the best snorkeling and diving in the dramatic coral canyons of Sombrero Reef, which provides homes to thousands of colorful tropical fish. There's also Molasses Reef and the underwater caves of French Reef.

If you like to snorkel, one of the best spots is the Looe Key National Marine Sanctuary (toll-free 800-942-5397), southeast of Big Pine Key. You'll see spectacular brain coral, tangles of staghorn and elkhorn coral, tall coral pillars, and purple seafans just below the clear water's surface, as well as several wrecked ships, including the British frigate H.M.S. Looe which sank in 1744. Some of the better dive shops along the Keys include the following:

• American Diving Headquarters: Key Largo, Toll-free 800-322-3483

• Captain Slate's Atlantis Dive Center: Key Largo, 305-451-3020

• Looe Key Dive Center: Ramrod Key, Toll-free 800-942-5397

• The Diving Site: Marathon, Toll-free 800-634-3935

• Tilden's Pro Dive: Marathon, 305-743-5422

On the Links and on the Courts

Several of the Keys' resorts have golf courses, but mostly you'll find par-three resort courses rather than regular ones. The eighteen-hole championship course at the Sombrero Country Club is probably the best in the Keys (800-433-8660, www.sombreroresort.com). For a fun round, try the Key Colony Beach Golf Course, a nine-hole par-three resort course in the Key Colony Beach development on Key Largo. There are no tee times, but clubs are available for rental (305-289-1533).

You won't find much tennis on the Keys, except for a court here or there at a resort. The Islamorada Tennis Club at Mile Marker 76.85 has four clay and two hard courts available day and night, plus a pro shop (305-664-5340).

Shopping

Being close to the mainland, Key Largo has a full complement of shopping centers, as well as the usual seaside T-shirt and souvenir shops. For handmade pottery, head to the Village Pottery on Islamorada, or if you're a fisherman, you'll love browsing through H. T. Chittum & Co. General Mercantile, also on Islamorada. For locally designed and made T-shirts, stop in at Handprints of the Keys in Marathon, where you can watch them being made and afterward buy some at discounted prices.