A Closer Look at the Great Blue Hole Dive Site in Belize
Jun 10, 2026
The Great Blue Hole is a large marine sinkhole off the coast of Belize inside Lighthouse Reef Atoll. It remains one of Belize’s best-known natural attractions and dive sites. Many visitors remember the site because the dive highlights geology as much as marine life.
Lighthouse Reef sits within the broader Belize Barrier Reef area, but the Blue Hole does not resemble a typical reef swim. Instead, the seafloor drops into a steep-walled basin with a crisp edge and a darker center. That sudden change in depth makes the approach visually striking.
From above, the Blue Hole appears as a dark circular pool surrounded by pale turquoise shallows. The formation measures roughly 1,000 feet (300 meters) across and extends more than 400 feet (120 meters) deep. Its nearly circular outline makes the boundary with the surrounding reef easy to spot even from a boat. The color shift comes from steep walls and a deeper interior beside a shallow reef platform…