Flat Cay
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
Flat Cay is a small uninhabited island off St. Thomas with several dive sites around its perimeter, and depths from 17 to 70 feet (5 to 21 m). It suits everyone from snorkellers to experienced divers.
The south side has dramatic boulder formations with swim-throughs, while the north side is a gently sloping reef that suits drift diving. The reef is a playground for tropical fish and slow-flying stingrays, and giant lobsters are seen at around 50 feet (15 m). A young sand shark has been spotted here.
Marine life here
Confirmed by our research team, reported by independent divers, or observed nearby via iNaturalist — each entry is labelled with its source.
Mustard Hill CoralPorites astreoidesReported here · unconfirmed
Massive Starlet CoralSiderastrea sidereaReported here · unconfirmed
Finger CoralPorites poritesReported here · unconfirmed
Boulder star coralOrbicella franksiReported here · unconfirmed
Lobed Star CoralOrbicella annularisReported here · unconfirmed
Greater Star CoralMontastraea cavernosaReported here · unconfirmed
BarracudaBarracudaReported here · unconfirmed
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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