The Great Blue Hole, its depths teeming with sharks and ancient mysteries, is one of the great wonders of the underwater world–and certainly some of the best scuba diving in Belize. Any scuba diver with an internet connection has undoubtedly spent hours staring at images of the Belize dive site’s majesty: angelfish, barracuda, corals, a prodigious shark population…oh, my! Just 45 miles off the coast, the famous 1000-foot-wide sinkhole is a quick boat trip from any dive shop in Caye Caulker or even Ambergris Caye.
The Blue Hole was a very well-kept secret among divers until 1971, when oceanographer Jacques Cousteau made the collapsed cave famous by diving in to measure its depths and origin. He clocked the Blue Hole at 125 meters deep. Interestingly, Cousteau also proved that the Hole was formed above-water and later submerged–he brought ancient stalactites to the surface, which could not have formed underwater. Greatly on account of Cousteau’s historic dives, the Blue Hole holds the prestigious designation of UNESCO World Heritage Site.
The Great Blue Hole formed as a result of the last Ice Age, more than 15,000 years in Earth’s past. When the Ice Ages pulled water from the oceans and locked it into the polar ice caps, sea level dropped accordingly. Parts of the Earth’s surface that are now underwater–the Blue Hole included–were exposed to the elements. The limestone roof of the cave that is now the Great Blue Hole was eroded by rainwater; it broke through and was covered by ocean water when the Ice Age ended, providing the scuba diver’s playground we all now know so well.
Because of the precipitous depth and shape of this phenomenon, the Blue Hole is not a site for inexperienced scuba divers. Divers who enter the Hole must know how to navigate and orient themselves in these unique conditions, as it may be fatal to become disoriented inside. Because of the inherent challenge of the site, scuba diving in Belize’s Great Blue Hole requires a PADI Deep Diver certification (or equivalent)–and you’ll be glad you have it. You’ll explore the Blue Hole’s network of underwater cave systems, bedecked with multicolored stalactites and stalagmites, as well as shivering in your fins at the sheer volume of sharks that shares the space with you.
Luckily for newer divers, much of the marine life is on the outside of the hole itself–so dive shops in San Pedro (as well as other dive shops in Belize) will be able to outfit and organize a Blue Hole trip for nearly any diver. The active coral formations of the Lighthouse Reef envelop the site, hosting marine animals such as sponges, worms, nurse and reef sharks, turtles, algae, gorgonian fans, tropical fish, giant groups, coral shrimp, and the rest of its Disney-movie-worthy population of undersea critters. No scuba diver will ever forget an experience like diving the Blue Hole.
If you’re already packing up your mask, here are some pointers: though the waters are warm throughout the year in the Ambergris Caye area, the best time to dive it is in the dry season (February to May). The murkiness of the rainy season is likely be an inconvenience even for experienced divers. It’s good to know that dive shops in Ambergris Caye (and most dive shops in Belize) will commonly accept US dollars. Also remember: the Blue Hole is deeper than the PADI Open Water limit! Get your PADI Deep Diver certification (or equivalent) before you go.