Islas Catalinas

A Catalinas day starts early. The Playas del Coco shops sell the islands as a separate advanced excursion, about 30 km south of Coco and under an hour by dive boat, and Tamarindo Diving meets its group at 6:40 am to fit equipment before boarding on Tamarindo beach. Boats do not anchor: every dive is a drift, and at La Punta that means a free descent on the shallow side of the island, then a run south with the current into deeper water. Expect surge, stronger currents and open-ocean swell, and a day trip rather than a base.

The islands are volcanic pinnacles, with steep walls that drop past 30 m, and La Pared ends over a coral garden. The draw is the open water beside the walls: oceanic manta rays four to seven metres across, schools of cow-nose rays, eagle rays and other pelagic fish that come in to hunt or to visit a cleaning station. Whitetip reef sharks live in the channel at La Pared and patrol the deeper water at La Punta, and turtles turn up too. Visibility of 12 to 30 m is often better than close to shore.

The Catalinas suit divers already comfortable with drift dives, deeper profiles and changing conditions. The sheltered north side and the shallow sandy patch between the rocks at Cuatro Piedras are rated for beginners, though current can make it hard to stay on the sand. Divers who want calmer water and shorter boat rides have the local sites closer to Coco. The Bat Islands further north are the other offshore day from the same shops.

Water averages about 28 °C, but a thermocline can drop it to 18 °C, and Summer Salt's rental kit is a 3 mm full wetsuit. November to April is the window built around the mantas, with sightings reported into May; outside it the islands still run as a drift and big-fish trip, but without the animal most divers book for.