Blue Holes - Rock Islands
Blue Holes is one of those Palau sites that really sticks with you, a genuinely unique experience. We love dropping through the main chimney, around 10 meters down, watching the light rays pierce the darkness. It’s like entering a cathedral. You come out into a massive cavern, then drift out to the wall at 30 meters or so. Look up, and you’ll often see reef sharks silhouetted against the blue. The wall itself is gorgeous, full of Blackside Hawkfish perched on corals and the occasional Golden Butterflyfish flitting past. We’ve spotted some tiny beauties here too, like the Palespot Eviota, if you take the time to really look. Current can pick up, so this isn't a beginner drift, but if you’re comfortable moving with the water, it’s a brilliant ride along the reef. We always check the tides; slack high is our favourite for the clearest water and easier entry.
- Location
- Rock Islands, Palau, Central & South Pacific
- Coordinates
- 7.137202, 134.222550
Marine Protected Area: Ngemelis Island Complex
Best Time to Dive in Rock Islands
The warmest water temperatures in Rock Islands occur in October, averaging 30.0°C. The coolest conditions are in February at 28.4°C.
Monthly Water Temperatures
- January: 28.8°C
- February: 28.4°C
- March: 28.8°C
- April: 29.3°C
- May: 29.8°C
- June: 29.9°C
- July: 29.8°C
- August: 29.7°C
- September: 29.9°C
- October: 30.0°C
- November: 29.9°C
- December: 29.6°C
Nearby Dive Sites in Rock Islands
- Big Drop Off - 20-40m (wall)
- Blue Corner
- Blue Corner (and Blue Holes)
- Chandelier Cave (cave)
- Chandelier Caves - 34m to 98m
- Chuyo Maru (wreck)
- German Channel - 21m (drift)
- Helmet Wreck - 34m to 98m (wreck)
- Iro - 16-131ft (5-40m) (wreck)
- Iro Maru Wreck Palau - 27m (wreck)
- Jake SeaPlane (wreck)
- Jellyfish Lake - Ongeim’l Tketau - 12m
- Lighthouse Channel (drift)
- Mandarinfish Lake - 16-131ft (5-40m)
- MT ARAYAT - 0m (wreck)
Nearest Dive Centres to Blue Holes
Marine Life in Rock Islands
Home to 198 recorded species including 171 reef fish, 15 sea cucumbers, 4 clams & mussels, 4 sea snails & nudibranchs, 2 starfish, 1 sea urchins.
Notable Species
- Boring Clam (Tridacna crocea) - Clams & Mussels
- Small giant clam (Tridacna maxima) - Clams & Mussels
- Black sea cucumber (Holothuria atra) - Sea Cucumbers
- Orange-lined Triggerfish (Balistapus undulatus) - Reef Fish
- Pinkfish (Holothuria edulis) - Sea Cucumbers
- Saddleback Butterflyfish (Chaetodon ephippium) - Reef Fish
- Greenfish (Stichopus chloronotus) - Sea Cucumbers
- Bristle-toothed Surgeonfish (Ctenochaetus striatus) - Reef Fish
- Burrowing urchin (Echinometra mathaei) - Sea Urchins
- Bullethead Parrotfish (Chlorurus sordidus) - Reef Fish
- Tigerfish (Bohadschia argus) - Sea Cucumbers
- Threadfin (Chaetodon auriga) - Reef Fish
- Telescopefish (Epibulus insidiator) - Reef Fish
- Banded Goatfish (Parupeneus multifasciatus) - Reef Fish
- Kihikihi (Zanclus cornutus) - Reef Fish
- Banded maori wrasse (Cheilinus fasciatus) - Reef Fish
- Sunburst Butterflyfish (Chaetodon kleinii) - Reef Fish
- Curryfish (Stichopus vastus) - Sea Cucumbers
- Butterfly fish (Chaetodon vagabundus) - Reef Fish
- Honeycomb Grouper (Epinephelus merra) - Reef Fish
Recommended Packing List for Blue Holes
Based on average water temperature of 29.5°C, currents 13 cm/s.
- Shorty or Rashguard - warm 30°C water needs minimal exposure protection
- Mask - essential for every dive
- Fins
- BCD - buoyancy compensator
- Regulator - your most safety-critical piece of gear
- Dive Computer - tracks depth, time, and NDL
- Surface Marker Buoy (SMB) - essential for boat pickups
- Dive Torch - useful for crevices and colour at depth
- Underwater Camera - capture your diving memories