Under the waters of the Verde Island Passage between Batangas and Mindoro is a treasure trove - 1,736 overlapping marine species in an area just 10x10-sq km. It’s the highest concentration of marine life in the world. The World Conservation Union (WCU) has declared the passage “the center of the centre of marine shore fish biodiversity,” dethroning Sulawesi, Indonesia.

Sea turtles, humphead wrasses, dolphins, sharks, sea snakes, giant groupers, clams, crabs thrive here among garden coral reefs and rock formations of every kind.

“Nearly 60 per cent of all marine species are located in the Verde Island Passage between Mindoro and Luzon,” said marine biologist Kent Carpenter of the WCU, who dubbed the area “the world’s blue water version of the Amazon River basin.”

Carpenter’s theory is that land barriers, surface temperatures, and restriction of currents isolated the sea basins around the country from one another, making it possible for the species to evolve in concentrated diversity.

“About 150 of the species can be found in the Philippines alone, and there are others still unidentified,” said Leslie de la Peña of the Philippine Commission on Sports Scuba Diving. “By locating the country as the world’s marine biodiversity hotspot, we could bring thousands of tourists and explorers to our coastal municipalities.”

Verde Island has 13 diving spots, among them San Agapito, Lito Cave and Mini-Canyon/Washing Machine. The TV channel Living Asia featured the island twice this year, with a shot of a school of dolphins.

San Agapito boasts of a submerged mountain with a pinnacle that drops off to 100 m or 330 ft. It’s home to sergeant majors, damsels, anthias, eels, nudibranchs, surgeon fishes, fusiliers, tunas, batfishes and jacks.

There are bubbles rising from the ocean floor, apparently due to volcanic activities at the site.

“There’s so much life down there. When divers speak of Verde Island, they think of San Agapito with its giant gorgonian fans and garden of corals,” said Virgilio Casingal, Verde Island Resort’s dive master and instructor.

On the sea surface of five underwater canyons, one can see whirlpools caused by the changing currents. The canyons have been formed by the water movements that spin divers in a roller-coaster ride. The bigger and wilder the currents, the more species of pelagics, trevallies, parrot fishes, frogfishes, tube worms, sea squirts and reef sharks there are to meet.

The current usually starts slow and gradually begins churning. Unexperienced divers are advised to stay close to the bottom and just watch the fishes roll.

Since not all tourists are willing to dare dive or snorkel, the island’s resort offers a glass bottom boat where passengers can get a view of the undersea without getting wet.

The legend of Jack Sparrow may be fiction but Verde Island was once the abode of pirates who attacked Batangas before residents sold their lands to the Pastor family that now runs the Verde Island Resort.

Centuries earlier, Spanish captain Juan Verde discovered the place, Christianised its tribes and named it after himself. Remnants of “Nuestra Señora Dela Vida”, a 1621 wooden galleon ship with cannons, terra-cotta jars and Ming porcelains has been discovered offshore.

Isla Verde is panoramic, with a west view of Mt Halcon, the 15th highest peak in the country. The resort owners made sure that no tree was cut to build the villas of concrete and bamboo. On a hill is also reportedly a proof of a deluge.

“Atop the Verde Island hill are stones awash in sea water, meaning, the water level was once about 300 m above sea level. The rock formation on the beach and atop the hill is the same,” said Edwin Bautista, executive assistant of the Pastor family.

The natural riches of the island and its seas have been preserved despite the place being a residential area. It’s a marine sanctuary where it’s legal for the villagers to fish.

“Down under you can take different dives—wall dive, drift dive, shallow dive - and enter a new world of corals, sea creatures, caves, canyons and mountains all within reach,” Casingal said.

The sixth international underwater photo competition tour “Celebrate the Sea Festival” will include the island in September. It’s just the place for adventurers and explorers like Jack Sparrow to stage endless photo shoots and acrobatics without sailing at world’s end.