Deep-Sea Fishing

You can arrange a day of deep-sea fishing at one of the numerous piers or travel agencies for $220 to $360 (£121-£198) for 4 hours, $420 (£231) for 6 hours, and $520 (£286) for 8 hours for up to four people; for up to eight people, the prices are $420 (£231) for 4 hours, $550 (£303) for 6 hours, or $680 (£374) for 8 hours. Marinas will sometimes assist in putting together a group. Charters include a captain, a first mate, bait, gear, and beverages. Rates are lower if you depart from Isla Mujeres or from Cozumel -- and frankly, the fishing is better closer to those departure points.

Dolphin Swims

On Isla Mujeres, you have the opportunity to swim with dolphins at Dolphin Discovery (tel. 998/877-0207 or 849-4757; www.dolphindiscovery.com). Groups of eight people swim with two dolphins and one trainer. Swimmers view an educational video and spend time in the water with the trainer and the dolphins before enjoying 15 minutes of free swimming time with them. Reservations are recommended, and you must arrive an hour before your assigned swimming time, at 10:30am, noon, 2pm, or 3:30pm. The cost is $139 (£76) per person for the Dolphin Royal Swim. There are less expensive programs that allow you to learn about, touch, and hold the dolphins (but not swim with them) starting at $79 (£43). Ferry transfers from Playa Langosta in Cancún are available.

La Isla Shopping Center, Bulevar Kukulkán Km 12.5, has an impressive Interactive Aquarium (tel. 998/883-0411, -0436, or -0413; www.aquariumcancun.com.mx), with dolphin swims and shows and the chance to feed a shark while immersed in the water in an acrylic cage. Guides inside the main tank use underwater microphones to point out the sea life, and even answer your questions. Open exhibition tanks enable visitors to touch a variety of marine life, including sea stars and manta rays. The educational dolphin program costs $65 (£36), while the dolphin swim is $135 (£74) and the shark-feeding experience runs $65 (£36). The entrance fee to the aquarium is $13 (£7.15) for adults, $9 (£4.95) for children, and it's open daily from 9am to 6pm.

Jet-Ski Tours

Several companies offer the popular Jungle Cruise, which takes you by small boat or WaveRunner (you drive your own watercraft) through Cancún's lagoon and mangrove estuaries out into the Caribbean Sea and a shallow reef. The excursion runs about 2 1/2 hours and costs $55 (£30), including snorkeling equipment and bottled water. Many people prefer the companies offering two-person boats rather than WaveRunners, since they can sit side by side rather than one behind the other.

Jet-ski operators and names offering excursions change often. To find out what's available, check with a local travel agent or hotel tour desk. The popular Aquaworld, Bulevar Kukulkán Km 15.2 (tel. 998/848-8327), calls its trip the Jungle Tour and charges $55 (£30) for the 2 1/2-hour excursion, which includes 45 minutes of snorkeling time. It even gives you a free snorkel, but has the less desirable one-behind-the-other seating configuration. Departures are daily every hour between 8am and 3pm.

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