Marine biologists describe the water off Puerto Galera as the centre of the centre of marine shorefish biodiversity. The Verde Island Passage, the strait dividing Mindoro from Luzon, shelters more coastal fish species per hectare than any comparable channel yet surveyed. A Puerto Galera diving package exists because of that figure rather than in spite of it. The town itself occupies the southern shoulder of the passage, folded into a harbour so well protected that Spanish galleons once wintered here, and UNESCO declared the surrounding coast a Man and Biosphere Reserve in 1973. The topography underwater is unusually compressed. Within fifteen minutes of Sabang and Muelle Bay lie more than thirty charted sites, most of them reachable by outrigger before the wind rises, which is why a Puerto Galera diving package tour is planned around tide tables rather than distance. The Canyons, a sequence of three coral ledges at 24 to 30 metres, is read by its current rather than its depth. Hole in the Wall offers a swim-through barely wider than a diver at roughly twelve metres. The Alma Jane, a 30-metre steel cargo vessel scuttled in 2003, carries soft coral along her railings and a permanent cloud of batfish above the holds. Shallower still, the Sabang Wrecks lie in sand at 18 metres, colonised by frogfish and pipefish. That density explains why Puerto Galera scuba diving established itself here decades before the island-hopping fleet arrived. Dive shops opened along Sabang's seawall in the 1980s, and the technical community followed, drawn by walls that drop past recreational limits within a short boat ride. The operators selling Puerto Galera diving package tours today inherit that infrastructure: compressors, chamber access in Batangas, and guides who read the Mindoro Strait by its colour. The reefs are managed rather than merely visited — mooring buoys replace anchors, several coves are closed to fishing, and the municipality collects a 120 PHP environmental user fee on entry, which funds reef patrols and waste collection. Guides working the Puerto Galera dive sites tend to describe the appeal in terms of restraint. Visibility rarely overwhelms; it simply holds steady, eight to twenty-five metres depending on tide. The interest lies in small things — nudibranchs grazing a sponge, a Coleman shrimp riding a fire urchin — and in the knowledge that this passage, 1.4 million hectares of it, is the richest shallow sea on the planet. That, quietly, is the case a Puerto Galera diving package makes.