La Cordillera Nature Reserve, Puerto Rico: the Reef Chain Around Icacos

What the La Cordillera nature reserve in Puerto Rico covers

The protected area runs to about 29,653 acres, or 120 km², and most of that figure is sea. The designation exists for the reef platform, the seagrass beds and the channels between the cays; the dry land amounts to a few small cays and rocky islets strung along the chain.

A recommendation made in 1978 became law on 2 January 1980, when the Third Extension of Planning Board Resolution JP PU-002 brought these waters under the island's Coastal Zone Management Plan. Eleven years later, in 1991, the reserve passed to the Departamento de Recursos Naturales y Ambientales, which administers it today. No tour company, marina or hotel manages any part of it.

Distance is why day trips work at all. The reserve boundary starts 1.5 nautical miles northeast of Fajardo, with the protected waters centred near 18°23'50" N, 65°36'15" W, so a boat leaving the Fajardo coast is inside the reserve minutes after clearing the shoreline. No public ferry runs into it. Every visit is made on a boat leaving the Fajardo and Ceiba coast or one of the marinas.

Cayo Icacos, the largest piece of land in the chain

Icacos holds about 0.659 km² (0.254 sq mi) of land, which makes it the largest uninhabited cay in the chain and the one almost every day trip uses. Nothing is built on it. Palms, sea grape scrub and rocky points are the whole inventory, and there are no restrooms, no drinking water, no food service and no bins, so whatever you carry ashore leaves again on the boat with you. No lifeguard watches the water anywhere on the cay, which leaves every swim and every snorkel down to your own judgement.

The reserve's own zoning sends day visitors to one strip of shore. The DRNA's 2017 field study calls the southwest sector Zone B and assigns it to bathers and water taxis, and that is where boats put people ashore. The same study maps Zone A for boaters off the northwest, Zone C for catamarans and the reef on the southern side, and Zone D around the mooring buoys and their reef. Ask which zone your boat works and you will know where the day gets spent.

One trace of pre-reserve use survives at the southern end, where a limestone quarry once worked with a short railway down to the pier. The ruins visitors notice today come from that operation. Designation followed in 1980, the department took over in 1991, and nothing has been built since.

The cays and reefs along the Arrecifes de la Cordillera line

The draft management plan lists the cays and islets from west to east, which is the order you pass them on a boat heading out from Fajardo. Two reef systems, Hermanos and Barriles, sit along the same line.

Ownership complicates the map. Isla Palominitos lies south of the main line, east of the Fajardo roadstead, while Cayo Lobos and Isla de Palominos are privately owned, their land excluded from the reserve even though the waters around them are protected. Along the whole chain the plan opens only four places to public landing: Cayo Icacos, the beach of Lobos, Cayo Diablo and Palominitos.

Mooring buoys went in at the most-visited sites, Cayo Icacos, Cayo Lobo, Cayo Diablo, Isla Palomino and Isla de Palominito, because anchors had already stripped bare patches in the seagrass meadows. Catamaran excursions from Villa Marina work the reef on the southern side of Icacos and the buoy reef, which the department found richer in fish and coral; private charters out of the Fajardo marinas usually run to Icacos or Palominos. Cayo Diablo and the rocky islets around Icacos and Cayo Ratones are seabird nesting ground where landing is not allowed, and the breeding season there runs March to September.

• Las Cucarachas
• Los Farallones
• Cayo Icacos
• Cayo Ratones
• La Blanquilla
• Cayo Diablo
• Hermanos and Barriles reefs
• Isla Palominitos, south of the chain
• Cayo Lobos and Isla de Palominos, private land inside protected waters

The rules across the reserve and who enforces them

Camping is prohibited on the cays and islets, and hunting and camping are both out on Cayo Icacos, so every trip is a same-day return timed to your boat. La Cordillera has never been designated a no-extraction area, and all kinds of water activities are allowed inside it. Noise is the exception, and it has an order of its own.

Administrative Order 2025-02, signed on 10 March 2025, prohibits voceteo, meaning high-volume sound systems mounted on vehicles and boats, across the reserves and beach zones the department manages, La Cordillera among them. The administrative fines reach $25,000 and can accumulate for each day a breach continues, and the Cuerpo de Vigilantes patrols the marine reserves to apply them. Leave the big speaker in the car.

In the water the damage is measurable. Departmental observers at Icacos logged at least one harmful action by 33 to 34% of snorkellers: disturbing an organism in 21.6% of cases, kicking the reef with fins in 19.6%, touching coral in 15.6%. What those fins land on is worth knowing. Staghorn coral, an endangered species, grows on the shallow tour reef south of the cay; 83 fish species across 33 families use these reefs; endangered sea turtles feed on the seagrass alongside them. Keep off the coral, keep your fins up, and let the captain tie to a buoy instead of dropping an anchor.

• No camping and no hunting on the cays; plan a return the same day.
• Landing by the public is limited to four places in the chain: Cayo Icacos, Lobos beach, Cayo Diablo and Palominitos.
• No high-volume sound systems on boats or vehicles, under Administrative Order 2025-02.
• No touching or standing on coral; use the mooring buoys instead of anchoring over seagrass.
• Carry out all your rubbish, since the cay has no trash collection.
• Questions about the reserve go to the Departamento de Recursos Naturales y Ambientales, Carretera 8838, km 6.3, Sector El Cinco, Río Piedras, San Juan, PR; post to San José Industrial Park, 1375 Ave. Ponce de León, San Juan, PR 00926; telephone +1 787-999-2200.

Choosing a boat trip inside the DRNA reserve at Fajardo

Operators working these waters do so under authorisation. The 2017 count came to seven catamaran operators holding that authorisation, with a combined ceiling of 487 passengers a day, alongside 18 authorised tour operators working south Icacos out of the marinas at Fajardo and Ceiba. The reserve as a whole takes something in the order of 10,000 recreational boats a year, and a survey in July 2005 found around 300 vessels of 20 to 60 feet anchored inside it at a single moment.

An early, guided boat that moors on the reef, feeds you on board and carries its own rubbish home leaves the least behind. Of the two catamaran trips listed on this site, the 7:00 a.m. check-in puts you over the reef well before the department's recorded peak hour of 2:00 p.m., while the 8:30 a.m. check-in buys a bathroom on board, which counts on a cay with none.

For the water itself, January through March is the driest and flattest stretch of the year, April turns into the rainy season, and the Atlantic hurricane season holds from 1 June to 30 November with its climatological high point on 10 September. Both tours below refund in full if you cancel at least 24 hours before the scheduled departure, which is the lever to pull when the forecast moves.

Questions people ask

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