Dive Site: Great Blue Hole

About Great Blue Hole

The Great Blue Hole, a globally renowned marine sinkhole, lies approximately 70 km offshore from Ambergris Caye, situated within the Lighthouse Reef Atoll in Belize. This colossal circular formation, measuring 300 meters across and plunging to depths of 122-126 meters, is a geological wonder that originated as a limestone cave thousands of years ago. As ocean levels rose, the cave flooded and its roof collapsed, creating the iconic Blue Hole. Its significance as a dive site was cemented by Jacques Cousteau, who listed it among his favorite dive locations. Diving the Great Blue Hole typically begins on a shallow reef shelf at about 10-12 meters, where divers can observe some coral life. The descent then follows the inner wall, transitioning into a dramatic underwater landscape. At depths around 30-40 meters, divers encounter impressive stalactites and limestone formations that evidence its past as a dry cave. While the interior is less vibrant than the surrounding reef, the sheer scale of the formations and the unique environment are central to the dive's experience. An alternative dive profile allows exploration of the rim's vibrant coral, offering a different perspective on the site. While the deep interior of the Blue Hole has limited coral due to lack of sunlight, the shallow reef around its rim teems with colorful fish, shrimp, groupers, and other Caribbean marine life. Inside the hole, the primary marine encounters are with sharks, including blacktip, Caribbean reef sharks, and occasionally bull and hammerhead sharks. Midnight parrotfish are also commonly seen. Visibility can often reach up to 60 meters, enhancing the dramatic views of the geological structures and marine life. This site is considered an advanced dive due to its depth, typically reaching 40 meters. Day boat trips from Ambergris Caye or Placencia can take 3-4 hours, often leading to additional dives on the Belize Barrier Reef or at nearby cays like Half Moon Caye. Liveaboard options provide more stable platforms for access. Divers should be prepared for deep diving conditions, including cooler temperatures at depth, and are advised to carry a dive light. Two distinct dive profiles are offered: a deep exploration of the cave formations and a shallower dive along the vibrant rim.

Dive site facts: Great Blue Hole

Depth

21–125 m

Typical dive

40 m, 8–10 min

Current

Mild to moderate

Visibility

20–40 m

Water temperature

26–29 °C

Entry

Boat

Level

Advanced, deep specialty recommended

Dive type

Deep, geological, cave, pelagic

Night dive

Not typical

Region / port

Lighthouse Reef Atoll, Belize

Coordinates

17.3189, -87.5339

Conditions & Currents

The Great Blue Hole typically has calm, motionless water inside, making it an excellent site for observing the deep formations without strong currents. The journey to the site can involve significant boat travel across open water, with waves growing outside the inshore reef until reaching the Lighthouse Reef Atoll. Surface conditions can be rough depending on the weather, requiring preparation for seasickness. The clear water inside the hole often allows for exceptional visibility, but divers should be aware of a noticeable thermocline as they descend to greater depths.

Marine life & sighting chances

Caribbean reef shark

common

Hammerhead shark

occasional

Eagle ray

occasional

Nurse shark

occasional

Green sea turtle

occasional

Hawksbill turtle

occasional

Loggerhead turtle

occasional

Nassau grouper

October to December · occasional

Whale shark

April to June · rare

Dive profile & how the dive runs

Your dive begins with a descent into the massive circular opening of the Blue Hole. The primary objective is to reach the impressive geological formations at approximately 40 meters. You will navigate around colossal stalactites and stalagmites that formed when the sinkhole was above sea level. Divers often enter a cavernous area at this depth, allowing a brief exploration of the ancient limestone structures. Maintaining excellent buoyancy control is crucial to avoid stirring up sediment and to protect the delicate formations. The dive at depth is typically short, around 8-10 minutes, due to the no-decompression limits. You will then make a slow ascent, observing the stark contrast of the deep blue walls against the lighter upper waters. A safety stop is conducted at 5 meters, often against the shallower rim of the hole, before returning to the surface.

Underwater photography

Capturing the grandeur of the Great Blue Hole demands specific photographic techniques. For the expansive underwater vistas and the dramatic stalactite formations, a wide-angle lens is essential. Consider a fisheye lens to encompass the immense scale of the sinkhole and the towering geological features. Due to the deep dive profile and reduced light penetration, external strobes are highly recommended to illuminate the formations and bring out detail and color. Position your strobes carefully to avoid backscatter from any suspended particles. Visibility is generally excellent, enhancing the striking contrast between the deep blue water and the ancient rock. Buoyancy control is paramount; avoid contact with the formations and ensure your fin kicks do not disturb the bottom sediment, which can quickly degrade photographic conditions. Aim to photograph other divers as scale references against the massive structures.

Combine with nearby dive sites

• Half Moon Caye Wall

  Known for abundant corals, sponges, and pelagic encounters.

• Long Caye Wall

  Features healthy reef structures and diverse marine life.

• The Elbow at Turneffe

  A prime location for large pelagic fish and strong currents.

• Aquarium

  Famous for its dense schools of fish and vibrant reef.

Getting there & logistics

Access to the Great Blue Hole is primarily via liveaboard vessels or long day trips from coastal towns like San Pedro on Ambergris Caye or Caye Caulker. The closest international airport is Philip S. W. Goldson International Airport (BZE) in Belize City. Day trips often involve a 2.5-hour boat ride each way and typically include two additional dives at other Lighthouse Reef Atoll sites, such as Half Moon Caye Wall. Liveaboards provide more direct access and can explore multiple sites within the atoll over several days. Marine park fees are required as the site is part of a UNESCO World Heritage area; these are usually included in dive package costs. Booking well in advance is advisable, especially during peak season from March to June, to secure spots on reputable operators' trips.

Safety & environment

Diving the Great Blue Hole is a deep dive, making advanced training and excellent buoyancy control critical. Divers must be certified Advanced Open Water and ideally have deep diving experience. The nearest recompression chamber is located in San Pedro, Ambergris Caye, which can be several hours away by boat depending on sea conditions and departure point from the Blue Hole. Emergency evacuation protocols involve transfer by boat to the mainland or San Pedro, followed by ground transport to the chamber. Due to the remote location and potential for long transfer times, comprehensive dive insurance that covers emergency medical treatment and evacuation is mandatory. Adhere strictly to your dive guide's instructions, maintain close proximity to the group, and monitor your depth and bottom time carefully. Avoid disturbing the delicate stalactite formations within the hole.

Who it suits — and who it doesn't

FAQ

Great Blue Hole FAQ

Liveaboards diving Great Blue Hole

These liveaboards may visit Great Blue Hole on selected itineraries — the exact dive sites depend on departure, weather and conditions.

Belize Aggressor IV

Belize

20 guests42.1 m

$356/day

Belize Aggressor III

Belize

18 guests33.5 m

$336/day