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.
Highlights
Season calendar
Dec – Apr
Peak dry season with best visibility. Ideal for wreck diving in Chuuk and manta encounters in Yap.
Oct – Nov
Transition to dry season. Good conditions with fewer crowds and better value.
May – Sep
Wet season with afternoon rain. Still diveable with mantas present in Yap year-round.
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
Leafy scorpionfish
occasional
Nudibranch
occasional
Anemonefish
commonDive 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
Suited for
- Advanced divers comfortable with currents
- Cavern and cave-certified divers
- Underwater photographers seeking dramatic light and pelagics
- Divers interested in diverse marine ecosystems
- Liveaboard enthusiasts
Less suited for
- Beginner divers or those new to currents
- Divers uncomfortable with overhead environments
- Divers with poor buoyancy control
- Individuals prone to seasickness on longer boat rides
- Those without comprehensive dive insurance
FAQ
Blue Holes FAQ
What kind of marine life can I expect to see at Blue Holes?
Are reef hooks necessary for diving Blue Holes?
What is the typical depth and visibility at Blue Holes?
Do I need special certification for the caverns at Blue Holes?
What is the best way to access Blue Holes?
Why dive Blue Holes from a liveaboard?
Blue Holes is one of Micronesia's signature dive sites. A liveaboard sleeps you on the water and puts you in the water for three to four guided dives per day, including dawn and night dives that day-boat operators rarely offer. You skip the daily commute back to port and reach quieter, less-crowded sites in the same region on a single trip.
Below are the liveaboards that include Blue Holes on their Micronesia itineraries.
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

Solitude Gaia
Micronesia

Palau Aggressor II
Micronesia

Black Pearl
Micronesia

Ocean Hunter 3
Micronesia

Pacific Master
Solomon Islands
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