Dive Site: Blue Holes

About Blue Holes

Blue Holes is an iconic dive site in Palau, located near the northwestern end of Ngemelis Island, offering a unique combination of cavern exploration and vibrant reef life. This site is frequently combined with dives at the renowned Blue Corner, forming a dynamic duo for divers seeking both architectural underwater beauty and prolific marine action. The dive provides a fascinating journey through interconnected caverns that open out onto a dramatic wall, revealing a diverse ecosystem. The topography transitions from an initial shallow reef plateau into several striking blue holes, which are natural openings in the reef that descend into larger caverns. These caverns are characterized by their intricate formations and the ethereal light filtering through overhead openings, creating a truly atmospheric experience. Beyond the caverns, the dive typically extends along a vibrant reef wall that plunges to significant depths, showcasing Palau's rich coral diversity with both hard and soft corals. Marine life here is abundant and varied, reflecting Palau's status as a marine biodiversity hotspot. Expect to encounter schools of pelagic fish, various shark species, and a host of reef inhabitants. The currents, which can be significant, act as a conveyor belt for nutrients, supporting the flourishing ecosystem and drawing in larger marine creatures. Diving Blue Holes often involves drift techniques, making it an exhilarating experience for well-prepared divers. The practical dive experience at Blue Holes is often part of a liveaboard itinerary, allowing optimal access and timing to maximize the conditions. The site demands good buoyancy control, especially within the cavern systems, and an awareness of current conditions. The reward is an unforgettable exploration of an underwater landscape that combines geological marvels with exceptional marine biodiversity.

Dive site facts: Blue Holes

Depth

5–30 m

Typical dive

12–25 m, 50–60 min

Current

Moderate to strong

Visibility

20–40 m

Water temperature

27–30°C

Entry

Liveaboard / boat entry

Level

Advanced, current experience essential

Dive type

Wall, drift, cavern

Night dive

Possible (check permits)

Region / port

Palau

Coordinates

7.113, 134.205

Conditions & Currents

Currents at Blue Holes, like many sites in Palau, are often moderate to strong and can be unpredictable, sometimes changing direction both horizontally and vertically. This site is typically a drift dive, where divers allow the current to carry them along the reef and through the caverns. Guides will provide thorough briefings on current direction, entry, and exit procedures, and the importance of staying streamlined and close to the reef to conserve energy and air. While reef hooks are primarily used at nearby Blue Corner for stabilization against strong currents, good buoyancy control and an understanding of drift diving techniques are crucial for navigating Blue Holes effectively. Visibility is generally excellent, often exceeding 20 meters, but strong currents can sometimes stir up sediment, especially within cavern entrances. Divers should be comfortable with varying current intensi

Marine life & sighting chances

Grey reef shark

common

Whitetip reef shark

occasional

Blacktip reef shark

occasional

Big-eye trevally

common

Bluefin tuna

occasional

Red snapper

common

Barracuda

common

Hawksbill turtle

occasional

Green turtle

occasional

Bumphead parrotfish

occasional

Spotted eagle ray

rare

Leafy scorpionfish

occasional

Nudibranch

occasional

Anemonefish

common

Dive profile & how the dive runs

Your dive at Blue Holes typically begins with a descent through one of the large, circular openings on the reef top, around 5 to 10 meters deep, leading into a spacious cavern. You'll explore these interconnected caverns, observing the unique geological formations and the interplay of light and shadow created by the overhead entrances. Maintain excellent buoyancy control to avoid contact with the delicate structures and the sand bottom. After navigating the cavern system, the route usually opens onto a dramatic vertical wall. From here, you'll embark on a drift along the wall, carried by the prevailing current, observing the abundant pelagic life and reef inhabitants. Depths generally range between 12 to 25 meters during this phase, though the wall continues much deeper. The turning point is often dictated by air consumption and current conditions, after which you'll begin a slow ascent. Your safety stop will be conducted in the shallower reef areas, often utilizing the slight currents to extend bottom time and observe the vibrant reef top.

Underwater photography

Blue Holes offers diverse photographic opportunities, from wide-angle shots of cavern interiors to macro subjects nestled within the reef. For the caverns, a wide-angle lens is essential to capture the scale and the striking light rays filtering from above; external strobes are beneficial for illuminating the darker sections and bringing out color. Buoyancy control is paramount to avoid disturbing sediment and to maintain a stable position for composition. Along the wall, a wide-angle setup is ideal for capturing schooling fish and pelagic encounters. For macro enthusiasts, bring a dedicated macro lens to find nudibranchs, small crabs, and other hidden critters within the coral and on cavern walls. A focus light will aid in spotting these smaller subjects. Always be mindful of your fins and equipment to prevent accidental contact with the environment, especially within the confined spaces of the caverns.

Combine with nearby dive sites

• Blue Corner

  Often combined with Blue Holes for a comprehensive dive experience.

• German Channel

  Known for manta ray cleaning stations and shark action.

• Ulong Channel

  A thrilling drift dive with abundant pelagic life.

• Chandelier Cave

  A unique cave system where divers can surface inside.

• Iro Maru

  A WWII wreck dive offering historical exploration.

Getting there & logistics

Access to Blue Holes typically involves a liveaboard cruise or daily boat trips from Koror, Palau's main city. The closest international airport is Roman Tmetuchl International Airport (ROR) on Babeldaob Island. Most liveaboard itineraries range from 7 to 10 days, covering a wide array of Palau's dive sites, including Blue Holes, Blue Corner, and German Channel. Divers are required to obtain a Koror State diving permit, which is often included in liveaboard packages or can be purchased through local dive operators. It's advisable to book well in advance, especially for peak season travel. Some liveaboards may also include permits for specific areas like Peleliu or Chandelier Cave, ensuring a seamless dive experience across the region.

Safety & environment

Diving at Blue Holes requires a high level of dive experience due to the potential for strong, unpredictable currents and overhead environments within the caverns. Excellent buoyancy control is critical to prevent disturbing the delicate ecosystem and to navigate confined spaces safely. Divers must adhere strictly to dive guide instructions, especially concerning entry and exit procedures and maintaining buddy contact in varying current conditions. The nearest recompression chamber is located in Koror, Palau. Evacuation in Micronesia can be complex and expensive, so comprehensive dive insurance, including coverage for medical emergencies and evacuation, is highly recommended. Always stay within your training limits and be aware of your air consumption, as currents can increase exertion.

Who it suits — and who it doesn't

FAQ

Blue Holes FAQ

Liveaboards diving Blue Holes

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

Palau Siren

Micronesia

16 guests

$500/day

Solitude Gaia

Micronesia

18 guests40 m

$310/day

Palau Aggressor II

Micronesia

18 guests32 m

$292/day

Black Pearl

Micronesia

24 guests

$390/day

Ocean Hunter 3

Micronesia

16 guests29 m

$350/day

Pacific Master

Solomon Islands

20 guests30 m

$268/day