Ulong Channel - Rock Islands
Ulong Channel isn't just a drift dive, it's a high-speed joyride through a natural aquarium. We love dropping in north of the channel, typically around 20 meters, and letting the current do all the work. It pulls you along a sandy bottom that rarely dips below 13 meters, past schools of spotted surgeonfish so thick they dim the light. Keep an eye out for batavian parrotfish chewing on coral and cleaner mimics darting around. The real magic happens on the channel walls. They’re absolutely packed with life, a constant parade of bicolour parrotfish, foxface, and tiny Queensland eviota. We've spent entire dives just hovering, watching the drama unfold. Look for the occasional cowry or sea olive tucked into a crevice. This is a dive that suits anyone who enjoys a thrilling drift and a relentless display of reef fish in a stunning, shallow setting. You’ll want to do it more than once; there’s just too much to take in on a single pass.
- Location
- Rock Islands, Palau, Central & South Pacific
- Coordinates
- 7.283438, 134.244690
- Type
- drift
Marine Protected Area: Ngerumekaol Spawning Area
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)
- 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)
Nearest Dive Centres to Ulong Channel
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 Ulong Channel
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