Diving in the Belize Blue Hole

As one of the world's most famous dive sites, Belize's Blue Hole captures the imaginations of scuba divers around the world. Pictures from the air show the Blue Hole to be exactly what it is, namely an enormous pit that plunges straight down through crystal clear waters, punching a distinctive hole through the surrounding seafloor. Diving the Blue Hole is a dramatic experience and a crowning gem of any dive trip to Belize.

  1. Identification

    • Sometimes called "the Great Blue Hole" because of its dimensions, the Blue Hole of Belize is an underwater vertical cave plunging through the center of a Caribbean atoll. This cavernous pit is thought to be the result of a previous cave system flooding and collapsing during the last Ice Age. The Blue Hole is roughly 60 miles east of Belize City, and was described by Jacques Cousteau as one of the world's top 10 dives.

    Features

    • According to National Geographic, the Blue Hole is 1,000 feet wide and over 400 feet deep. The walls of the pit are largely featureless until cave features like stalagmites begin to appear at between 110 and 130 feet. Between 130 and 150 feet, small tunnels branching off from the main pit start to appear, and below this the Blue Hole begins to drop at an angle rather than straight down. Water temperature at the surface is in the high 80s Fahrenheit, but at the 130-foot mark it hovers in the mid-70s. Visibility in the Blue Hole is high, often between 150 and 200 feet.

    Diving the Blue Hole

    • Most divers visit the Blue Hole of Belize either on a boat dive trip from Ambergris Caye or on a live-aboard scuba diving cruise out of a port in mainland Belize. For recreational divers, the dive is about the drama of the descent into the deep blue abyss. The recreational dive limit is usually 130 feet, although in the Blue Hole this is often pushed to 140 feet. Divers descend to this level, still far above the bottom of the pit, have a look around for several minutes, and return to the surface.

    Sea Life

    • Very little sea life actually resides inside the Blue Hole, although divers do occasionally see the odd reef shark or bull shark emerge from the blue gloom beneath them. The outside of the Blue Hole is another story. As a Caribbean atoll, the circular rim of the Blue Hole is essentially one big fringing reef, encrusted with corals and teeming with sea life such as moray eels, angelfish, fat groupers, jacks and damselfish.

    Hazards

    • With few visual references and nothing to grab onto, divers exploring the Blue Hole must have excellent buoyancy control and keep a close eye on their depth gauges. The first risk is in descending too far without realizing it, as a slow-but-steady descent can drop a diver from 130 feet to 160 feet or deeper in a matter of minutes. The other risk is in ascending too fast, and ascent rate is best monitored simply by watching the bubbles exhaled from the scuba mouthpiece. So long as a diver ascends more slowly than her bubbles, she is safe. For these reasons and the depth of the dive, dive operators in Belize require Advanced Open Water certification or the equivalent to dive the Blue Hole.