This dive site is considered as the second best coral reef site within Subic Bay. Nabasan Reef is located at the South-West part of Triboa Bay and is often used as a training ground for less experienced divers. The site offers a drop-off wall starting at a depth of approximately 4 meters, and continues down past 20 meters, with the major part of the reef between 6 - 17 meters.
The reef is mostly made up of hard coral types with a frequent present of both sea whips and sea anemones. The corals are home to a wide variety of reef fish species. Bluespotted stingrays and pufferfish are common at this site. Waters here are usually clear, making this dive site good for underwater photography and a regular dive spot for Discover Scuba Diver and Open Water courses.