Castle Rock
Conditions & tides
Scored by DiveConnect's site-physics model
Marine forecast via Copernicus Marine. Score is a rule-based guide from swell/wind vs. the site's exposure — always dive your own assessment.
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About this site
Castle Rock is a submerged rocky seamount in Komodo National Park, Indonesia, rising from the seafloor to a shallowest point of 10 m with a maximum depth of 30 m. The bottom is rock, and the site is known for its pelagic action, drawing divers specifically for shark encounters and open-water species aggregations.
The seamount's rocky terrain drops to 30 m and is exposed to open-ocean currents, making it one of the more demanding sites in the park. Currents are variable and can be strong, with unpredictable shifts, downcurrents, washing-machine eddies, and turbulence all present. A negative entry is required, and the deep edges and blue-water environment add to the challenge. The site suits Advanced Open Water certified divers at minimum, and the conditions lean toward the technical end of recreational diving.
Marine life at Castle Rock centres on pelagics: white-tip sharks, grey reef sharks, whitetip reef sharks, dogtooth tuna, chevron barracuda, giant trevallies, mackerel, fusiliers, surgeonfish, eagle rays, and bottlenose dolphins are all recorded here. The site is particularly productive for shark activity.
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Conditions vary with the tides and season; diving at slack water around peak high or low tide reduces current exposure. Water temperature ranges between 24–29 °C, and visibility is generally good. The site is affected by northerly swells December through March, and the broader April-to-November window covers the most reliable diving period.
Marine life here
Confirmed by our research team, reported by independent divers, or observed nearby via iNaturalist — each entry is labelled with its source.
Reef sharkReef sharkReported here · unconfirmed
Jack / amberjackJack / amberjackReported here · unconfirmed
GrouperGrouperConfirmed present · 2 independent sources
SnapperSnapperConfirmed present · 2 independent sources
SurgeonfishSurgeonfishConfirmed present · 3 independent sources
Manta rayManta rayConfirmed present · 4 independent sources
BannerfishBannerfishReported here · unconfirmed
Whitetip Reef SharkTriaenodon obesusReported here · unconfirmed
Bignose UnicornfishNaso vlamingiiReported here · unconfirmed
Giant MorayGymnothorax javanicusReported here · unconfirmed
Giant TrevallyCaranx ignobilisReported here · unconfirmed
Moorish IdolZanclus cornutusReported here · unconfirmed
Yellow BoxfishOstracion cubicumReported here · unconfirmed
Clark's AnemonefishAmphiprion clarkiiReported here · unconfirmed
Blacklip ButterflyfishChaetodon kleiniiReported here · unconfirmed
Schooling BannerfishHeniochus diphreutesReported here · unconfirmed
Sixband AngelfishPomacanthus sexstriatusReported here · unconfirmed
Hammerhead sharkHammerhead sharkConfirmed present · 2 independent sources
MackerelMackerelConfirmed present · 4 independent sources
Napoleon (humphead) wrasseNapoleon (humphead) wrasseConfirmed present · 7 independent sources
Eagle rayEagle rayConfirmed present · 5 independent sources
BatfishBatfishConfirmed present · 3 independent sources
TunaTunaConfirmed present · 10 independent sources
TrevallyTrevallyConfirmed present · 15 independent sources
BarracudaBarracudaConfirmed present · 11 independent sources
SweetlipsSweetlipsReported here · unconfirmed
Nurse sharkNurse sharkReported here · unconfirmed
Bumphead parrotfishBumphead parrotfishReported here · unconfirmed
FusilierFusilierConfirmed present · 7 independent sources
Durable tips from divers — access, hazards, marine life, facilities. For day-of conditions, use the report tool in the conditions card above.
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