The Giant Pacific Manta Ray of Guanacaste, Costa Rica
I’m at ‘Big Scare’, Bat Islands, and as I descend to 30 meters and hover-in-wait for a famous bull shark encounter suddenly the sky goes dark and a shadow looms over my bubbles. I look up. The clear visibility we are blessed with today allows me to see the full silhouette of a giant manta ray gracefully moving across my line of vision to the sun. I wasn’t expecting it and it takes my breath away for a few seconds. It flies on into the distance.
That was a few years back and I have seen many since then. Each time is as exhilarating because these beautiful animals can reach 7m in diameter and 3000lbs in weight. Perhaps these creatures are a diver’s favourite because they like to play with bubbles and acrobatically manoeuvre slowly among the dive groups making them great photography subjects.
Contrary to the stingray, the giant manta ray does not have a stinging barb and is not a bottom feeder. It feeds by gliding through the water and filtering zooplankton (microscopic creatures) with its scoop shaped mouth. Life expectancy is 50 years and older, one ray was thought to have lived to 100 years old. Reproduction occurs near the surface, no deeper than a couple of meters, where the male pursues the female often followed closely by other suitors. There is a 12 month gestation period and, like sharks, the eggs hatch inside the mother and she will give birth to only 1 or 2 live young. Like sharks it will also be another 2 years before they mate again.
In the Guanacaste Pacific west coast of Costa Rica they can be found at both Bats and Cats: The Bat Island (Islas Murcielago) and Catalina Islands. Both are a good 45 mins – 1 hour by boat depending on conditions. The seasons for trips out to these Islands are November to May for the Catalinas and May to November for the Bat Islands. So there are year-round opportunities to see them although nothing is ever guaranteed.
Both dive sites are for advanced divers because of the depths and the currents. If you don’t have an advanced license consider getting one before you book a day trip to see the mantas. Water is warmer in the summer so anything from a 3mm – 5mm is expected. During winter season you may need to upgrade to 7mm, hoods and gloves to be comfortable in the 20c/66f water.
As well as manta ray encounters underwater, you can expect to see pods of dolphins, humpback whales in the season and tons of interesting life on the way to and from the dive sites.