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Hotels, dive operators, gear, and how to get here are on the Rock Islands location page.
Overview
A triangular reef plateau jutting off the northwest tip of Ngemelis Island, where Palau's barrier reef drops sharply into open ocean and currents accelerate around the point. Divers descend to a 15-20 m ledge, set a reef hook into rubble, and watch a near-permanent rotation of grey reef sharks, schooling bigeye trevally, chevron barracuda, and Napoleon wrasse hold against the flow. Unhook on the inside for a drift past hard coral and the occasional spotted eagle ray. Currents shift direction and strength quickly — the site is the reason Palauans invented the reef hook.
Briefing note
Permit: Rock Islands / Koror State permit plus the Palau Pristine Paradise Environmental Fee (paid on arrival, valid for the trip). Advanced Open Water minimum; previous reef-hook and drift experience expected. Currents can shift direction mid-dive — listen to the briefing on which way the hook faces. March-April peak for shark numbers.
What you'll see
8 species curated- year-roundGrey reef shark
- year-roundWhitetip reef shark
- year-roundNapoleon wrasse
- year-roundBigeye trevally
- year-roundChevron barracuda
- year-roundBumphead parrotfish
- year-roundHawksbill turtle
- rareSpotted eagle ray
Sightings evidence
1 record on file- high confidenceGrey reef shark
- Last confirmed
- May 2026
- Recent records
- 198 within 10 km
Sources & methodology
How we summarise this
We aggregate confirmed occurrence records from GBIF and OBIS within a fixed radius of each dive site. Occurrence records confirm presence and reveal seasonality clustering, but they DO NOT measure per-dive probability — there is no eligible-effort denominator. We deliberately do not publish a numeric '% chance of sighting' from this data.
Sources
- Global Biodiversity Information Facility — GBIF Secretariat
- Ocean Biodiversity Information System — IOC-UNESCO
- OBIS-SEAMAP — Duke University Marine Geospatial Ecology Lab / OBIS
- iNaturalist — California Academy of Sciences & National Geographic Society
- IUCN Red List of Threatened Species — International Union for Conservation of Nature
- WoRMS — World Register of Marine Species — Flanders Marine Institute (VLIZ)
- FishBase — FishBase Consortium
- Atlas of Living Australia — CSIRO / GBIF Australia
- REEF Volunteer Fish Survey — Reef Environmental Education Foundation
Conditions
| Month | Water | Visibility | Current |
|---|---|---|---|
| Jan | 27–28 °C | 20–30 m | strong |
| Feb | 27–28 °C | 25–35 m | strong |
| Mar | 28–29 °C | 25–35 m | moderate |
| Apr | 28–30 °C | 25–35 m | moderate |
| May | 29–30 °C | 20–30 m | moderate |
| Jun | 29–30 °C | 15–25 m | moderate |
| Jul | 29–30 °C | 15–25 m | moderate |
| Aug | 29–30 °C | 15–25 m | moderate |
| Sep | 29–30 °C | 15–25 m | moderate |
| Oct | 28–30 °C | 15–25 m | moderate |
| Nov | 28–29 °C | 20–30 m | moderate |
| Dec | 27–29 °C | 20–30 m | strong |
Season calendar
Peak season highlighted · current month outlined
Gear for this site
Beyond the basic kit- Reef hook — Currents up to 3 knots reverse direction at slack. Hooking into rubble at the 15-20 m ledge is the only practical way to watch the shark line without burning air.
- Surface marker buoy — Drift exits over open water — operators require an SMB deployed on ascent for boat pickup.
Next step
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Hotels, liveaboards, dive operators, gear recommendations, and travel logistics for the whole region.
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