The Great Blue Hole: A 400 Foot Deep Diver’s Paradise in Belize
In 1971, legendary French marine explorer Jacques Cousteau journeyed to an obscure sinkhole in Belize and dubbed its royal blue waters one of the best diving spots in the world. A circular expanse of water dubbed The Great Blue Hole by a British diver is visible from space, and contains a stunning network of submerged caves that contain aquatic and geological wonders that have wowed even the most seasoned divers.
Countless divers have explored the The Great Blue Hole’s shallow waters. Sea turtles, midnight parrotfish, colorful coral reefs, and eels swirl just below The Great Blue Hole’s azure surface. In 2018, a submarine crew decided to explore The Great Blue Hole’s deepest depths. Once the submarine crew descended about 300 feet, they entered a dead zone that did not support plant or animal life of any kind. Scientists attribute the dead zone to an inhospitable cloud of hydrogen sulfide which essentially suffocates any living thing that it comes in contact with. Below the border of the dead zone, scientists spotted several artifacts of modern life that had been sucked into the lower depths of the sinkhole—including a soda bottle and camera which most likely contained some lovely shots of Belize. The submarine crew even spotted more than one deceased human being. The bodies most likely belonged to explorers and tourists who were swept away by the sinkhole. The submarine crew decided that it was best to leave the sunken bodies undisturbed. The deathly quiet bottom of the seafloor is a peaceful resting place for any lifeless human.
The 2018 submarine crew who journeyed to the bottom of The Great Blue Hole also discovered stalactites. Stalactites signal that The Great Blue Hole was once a massive cave that formed on dry land. The vertical orientation of certain submerged cave features suggests that there has been a great deal of geologic activity that has changed The Great Blue Hole’s position over time—in addition to rising sea levels which caused water to rush in.
Erosion from powerful storms and the constant churning of ocean waves is slowing causing The Great Blue Hole to fade away. Diving enthusiasts still have several centuries to enjoy the arresting beauty of The Great Blue Hole.
If you’re going to brave the waters of The Great Blue Hole, it is important that you refine your scuba skills at a more tame location before attempting to navigate the sharp ledges and spiky coral of one the world’s most celebrated yet treacherous diving spots. More than a few inexperienced divers have been sucked into the depths of The Great Blue Hole’s dead zone. You can always journey to the edge of The Great Blue Hole by boat and gaze into its turquoise interior. It is incredible to consider that The Great Blue Hole is lined with silt that dates back to the time before the Mayan Empire. The Great Blue Hole is a stunning aquatic geologic history book that reveals so much about the epochs that preceded our current era.
UnusualPlaces Field Notes
- Location
- Great Blue Hole, Lighthouse Reef Atoll, Belize (offshore dive-site area)
- Coordinates
- 17.3160334, -87.5347494
- Access
- The Great Blue Hole is an offshore sinkhole at Lighthouse Reef Atoll, about 43 miles from mainland Belize; there is no land entrance. Visitors reach it by a booked boat trip. One San Pedro operator’s full-day trip includes the Blue Hole, Half Moon Caye Wall and Long Caye Aquarium; its deep dive reaches about 130 ft (40 m), requires Open Water certification and recent dive experience, and is subject to dive-team approval. Snorkelling may be offered as an alternative on the same offshore trip.
- Admission
- Paid boat/diving trip required; there is no general walk-up admission. Belize Pro Dive Center’s current listed package is US$285 plus 12.5% GST (US$35.63) and a US$40 marine-park fee, or US$360.63 total; optional dive-gear rental is listed at US$33.75. This is one operator’s package, not a universal park tariff; confirm the booking total and conditions.
- Time needed
- Belize Pro Dive Center describes its three-dive Lighthouse Reef outing as about 11 hours from check-in to return, with an approximately 2.5-hour boat ride each way. The Great Blue Hole dive itself is about 25–30 minutes; the overall trip also includes two other dive sites and Half Moon Caye.
- Best season
- PADI identifies April–June as the best general period for diving in Belize’s outer cayes and atolls. A dive-season guide describes February–June as the calmer dry-season window and specifically discusses Lighthouse Reef and the Great Blue Hole. These are regional conditions, not a guarantee; offshore operators can reschedule for weather.
- Opening hours
- There are no public site opening hours or walk-in access. Visits are by scheduled boat/diving operators; Belize Pro Dive Center lists trips daily subject to confirmation, with a 5:30 a.m. check-in and 6:00 a.m. departure from San Pedro for its package. Confirm the selected operator’s date and weather status.
- Location checked
- 2026-09-26
- Facts checked
- 2026-10-22
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