Sea Ventures Dive Center (Carr. 3, km 51.2, Fajardo, www.divefajardo.com , 787/863-3483 or 800/739-3483, fax 787/863-0199) operates three dive centers on the east coast, one in Fajardo , one in Guanica, and the other at Palmas del Mar , offering dive and snorkel trips to local reefs, Vieques, Culebra, and Cayo Santiago (Monkey Island) in Naguabo . Rent equipment or bring your own. The company also operates a dive center at the Copamarina Beach Resort in Guanica. Reservations are required.
Las Tortugas Adventures (4 Calle La Puntilla, San Juan, 787/725-5169, info [at] kayak-pr [dot] com, www.kayak-pr.com ) offers a variety of half- and full-day snorkeling and kayak tours on the east coast, launching from Bahía Las Croabas in Fajardo. Tours include Las Cabezas de San Juan in Fajardo , the bioluminescent lagoon, the mangrove forest in Piñones , and excursions to Cayo Icacos, Cayo Diablo, and Monkey Island. No experience is necessary, and all equipment is provided. Reservations are required.
East Island Excursions (Puerto Del Rey Marina, Fajardo, 787/860-3434 or 877/937- 4386, fax 787/860-1656, www.eastwindcats.com ) offers sailing and snorkeling trips aboard a 62-foot sailing catamaran with a glass bottom and a slide, a 65-foot power catamaran, or a 45-foot catamaran. Excursions are available to Vieques , Culebra , Culebrita, and St. Thomas . Reservations are required.
Caribbean School of Aquatics (Villa Marina, Fajardo, 787/728-6606, www.sail  diveparty.com) advertises itself with the slogan “Sail Dive Party” despite the scholarly name of its operation. It offers snorkeling, diving, and sailing trips to Vieques and Culebra aboard catamarans and sailing sloops. Reservations are required.
Traveler (Carr. 987, km 1.3, Villa Marina, Fajardo, 787/863-2821 or 787/396-0995, fax 787/801-0608, puertoricotraveler [at] hotmail [dot] com, www.travelerpr.com ) offers snorkeling and sailing on a 54-foot Catamaran. Trips depart from Villa Marina at 1 p.m., and transportation can be arranged from San Juan . Group rates and charter packages are available.
Kayaking Puerto Rico (787/435-1665 or 787/564-5629, info [at] kayakingpuertorico [dot] com, www.kayakingpuertorico.com ) offers combination kayaking and snorkeling expeditions, as well as bioluminescent plankton tours in Las Cabezas de San Juan’s Laguna Grande .