The Tunnel

The Tunnel is an advanced dive site on Guam's eastern coast, featuring a dramatic swimthrough passage carved through the limestone reef. Divers enter through a wide opening on the reef top and navigate a coral-lined tunnel that exits onto the outer reef wall, creating a thrilling transition from enclosed space to open blue water. The tunnel walls are decorated with soft corals, sponges, and encrusting organisms, while the exit point offers views of patrolling grey reef sharks and pelagic fish. This geological feature is one of Guam's most unique and exciting dive experiences.