Canoeing & Kayaking -- Biscayne National Park affords excellent canoeing, both along the coast and across the open water to nearby mangroves and artificial islands dotting the longest uninterrupted shoreline in the state of Florida. Because tides can be strong, only experienced canoeists should attempt to paddle far from shore. If you do plan to go far, first obtain a tide table from the visitor center and paddle with the current. Free ranger-led canoe tours are scheduled from 9am to noon on the second and fourth Saturdays of the month between January 10 and April 24; phone for information. You can rent a canoe at the park's concession stand for $12 an hour. Two-person kayaks go for $16 an hour. Call tel. 305/230-1100 for reservations, information, ranger tours, and boat rentals. You can also view information on the website of the park's concession, www.biscayneunderwater.com.

Fishing -- Ocean fishing is excellent year-round at Biscayne National Park; many people cast their lines from the breakwater jetty at Convoy Point. A fishing license is required. Bait is not available in Biscayne National Park, but it is sold in adjacent Homestead Bayfront Park. Stone crabs and Florida lobsters can be found here, but you're allowed to catch these only on the ocean side when they're in season. There are strict limits on size, season, number, and method of take (including spearfishing) for both freshwater and saltwater fishing. The latest regulations are available at most marinas, bait-and-tackle shops, and the park's visitor centers; or you can contact the Florida Fish and Wildlife Conservation Commission, Bryant Building, 620 S. Meridian St., Tallahassee, FL 32399-1600 (tel. 850/488-0331). For those looking to learn a little about fishing, Biscayne National Park offers a free class, The Fisheries Awareness Class, given on the third Wednesday of every month (during even-numbered months, classes are in Spanish) from 6 to 9:30pm at Suniland Park, 12855 S. Dixie Hwy (tel. 305/230-1144, ext. 3089), in Miami.

Hiking & Exploring -- As the majority of this park is underwater, hiking is not the main attraction here, but there are some interesting sights and trails nonetheless. At Convoy Point, you can walk along the 370-foot boardwalk and along the half-mile jetty that serves as a breakwater for the park's harbor. From here, you can usually see brown pelicans, little blue herons, snowy egrets, and a few exotic fish.

Elliott Key is accessible only by boat, but once you're there, you have two good trail options. True to its name, the Loop Trail makes a 1.5-mile circle from the bayside visitor center, through a hardwood hammock and mangroves, to an elevated oceanside boardwalk. You'll likely see land crabs scurrying around the mangrove roots.

Reopened in 1998, Boca Chita Key was once a playground for wealthy tycoons, and it still has the peaceful beauty that attracted elite anglers from cold climates. Many of the historic buildings are still intact, including an ornamental lighthouse that was never put to use. Take advantage of the tours, usually led by a park ranger and available every Sunday in winter only at 1:30pm. The tour, including the boat trip, takes about 3 hours. The price is $35 for adults, $25 for seniors, and $20 for children 11 and under. However, call in advance to see if the sea is calm enough for the trip -- the boats won't run in rough waters.

Snorkeling & Scuba Diving -- The clear, warm waters of Biscayne National Park are packed with colorful tropical fish that swim in the offshore reefs. If you don't have your own gear, or if you don't want to lug it to the park, you can rent or buy snorkeling and scuba gear at the full-service dive shop at Convoy Point. Rates are in line with those at mainland dive shops.

The best way to see the park from underwater is to take a snorkeling or diving tour operated by Biscayne National Underwater Park, Inc. (tel. 305/230-1100; www.nps.gov/bisc). Snorkeling tours depart at 1:30pm daily, last about 3 hours, and cost $38 per adult and $30 per child, including equipment. There are also weekend two-tank dives for certified divers; the price is $75, including two tanks and weights. Make your reservations in advance. The shop is open daily from 9am to 5pm.

Before entering the water, be sure to apply waterproof sunblock -- once you begin to explore, it's easy to lose track of time, and the Florida sun is brutal, even during winter.

Swimming -- You can swim off the protected beaches of Elliott Key, Boca Chita Key, and adjacent Homestead Bayfront Park, but none of these match the width or softness of other South Florida beaches. Check the water conditions before heading into the sea: The strong currents that make this a popular destination for windsurfers and sailors can be dangerous, even for strong swimmers. Homestead Bayfront Park is really just a marina next to Biscayne National Park, but it does have a beach and picnic facilities, as well as fishing areas and a playground. It's located at Convoy Point, 9698 SW 328th St., Homestead (tel. 305/230-3034).

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.