The continental shelf, which surrounds Puerto Rico on three sides, is responsible for an abundance of coral reefs, caves, sea walls, and trenches for scuba diving and snorkeling.
Open-water reefs off the southeastern coast near Humacao are visited by migrating whales and manatees. Many caves are located near Isabela on the west coast. A large canyon off the island's south coast is ideal for experienced open-water divers. Caves and the sea wall at La Parguera are also favorites. Vieques and Culebra islands have coral formations. Mona Island offers unspoiled reefs at depths averaging 80 feet (24m), with an amazing array of sea life. Uninhabited islands, such as Icacos, off the northeastern coast near Fajardo, are also popular with snorkelers and divers alike.
These sites are now within reach, because many of Puerto Rico's dive operators and resorts offer packages that include daily or twice-daily dives, scuba equipment, instruction, and excursions to Puerto Rico's popular attractions.
Introductory courses for beginners start at $125, and two-tank dives for experienced divers begin at around $85, but most cost at least $125.
In San Juan, try Caribe Aquatic Adventures, Normandie Hotel San Juan, Calle 19 1062, Villa Nevarez (tel. 787/281-8858), or Ocean Sports (Av. Isla Verde 77; tel. 787/268-2329).
Diving off the east, southwest, or northwest coasts is more rewarding, however.
In Rincón, there's Taíno Divers, Black Eagle Marina at Rincón (tel. 787/823-6429), which offers trips to the waters surrounding Desecheo Island natural reserve.
The ocean wall in the southwest is famous, with visibility ranging from 100 to 120 feet (30-37m) and reefs filled with abundant sea life. Paradise Scuba Center, Hotel Casa Blanca Building, at La Parguera (tel. 787/899-7611), and Mona Aquatics, Calle José de Diego, Boquerón (tel. 787/851-2185), are two good operators in the area.
In Guánica, there's Sea Venture Dive Copamarina (tel. 787/821-0505, ext. 729), part of the Copamarina Beach Resort.
The Dive Center at the Wyndham Rio Mar Beach Resort (tel. 787/888-6000) is one of the largest in Puerto Rico.
Elsewhere on the island, several other companies offer scuba and snorkeling instruction.
Because of its overpopulation, the waters around San Juan aren't the most ideal for snorkeling. In fact, the entire north shore of Puerto Rico fronts the Atlantic, where the waters are often turbulent.
Yet there are some protected areas along the north coast that make for fine snorkeling, even in surf capitals such as Rincón and Aguadilla. Many of the best surfing beaches in winter turn into a snorkeler's paradise in summer when the waves calm down.
The most ideal conditions for snorkeling in Puerto Rico are along the shores of the remote islands of Vieques and Culebra.
The best snorkeling on the main island is found near the town of Fajardo, to the east of San Juan and along the tranquil eastern coast.
The calm, glasslike quality of the clear Caribbean along the south shore is also ideal for snorkeling. The most developed tourist mecca here is the city of Ponce. Few rivers empty their muddy waters into the sea along the south coast, resulting in gin-clear waters offshore. You can snorkel off the coast without having to go on a boat trip. One good place is at Playa La Parguera, where you can rent snorkeling equipment from kiosks along the beach. This beach lies east of the town of Guánica, to the east of Ponce. Here tropical fish add to the brightness of the water, which is generally turquoise. The addition of mangrove cays in the area also makes La Parguera more alluring for snorkelers. Another good spot for snorkelers is Caja de Muertos off the coast of Ponce. Here a lagoon coral reef boasts a large number of fish species.
Even if you are staying in San Juan and want to go snorkeling, you are better off taking a day trip to Fajardo, where you'll get a real Caribbean snorkeling experience, with tranquil, clear water and stunning reefs teaming with tropical fish. Several operators offer day trips (10am-3:30pm) leaving from Fajardo marinas, but transportation to and from your San Juan hotel can also be arranged. Prices start at around $99.