doe.ky · Official Map
Government moorings map listing Big Tunnels and its mooring depth.
Big Tunnels
Big Tunnels is a boat-access tunnel dive on Grand Cayman's west wall.
Scuba DivingBoatAdvanced17m - 32m
PinnacleReefWall
Local operator required
Boat access is the practical model, with the site marked by a mooring line.
Plan for boat access, overhead swim-throughs, and a wall exit on one of Grand Cayman's best-known sites.
About Big Tunnels
Big Tunnels is a boat-access west-wall dive in Grand Cayman with a limestone pinnacle, tunnel swim-throughs, and a coral archway that opens toward the wall. It is known for dramatic passages, steady coral growth, and a route shape that feels more like underwater canyoning than a simple reef drift. The west side is usually calm, but the site still suits divers comfortable with overhead space, depth, and the occasional current pulse.
Safety & Access
Site Conditions
Overhead environmentStrong current
Safety Notes
The tunnel and wall route requires buoyancy control, gas awareness, and comfort in overhead spaces; current can show up in the passages and at the safety stop.
Where Is Big Tunnels?
Featured Operators
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Local Intel For Big Tunnels
Community notes to help plan your visit.
Scuba Diving
Expect a tunnel swim-through, coral archways, and a wall exit with strong photo potential.
Wildlife at Big Tunnels
Species commonly reported at this site, with direct links into their wildlife guides.
Research Estimate At Big Tunnels
Access · 4/5Simple entry
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Coral · 5/5Pristine, vibrant coral
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Aquatic Life · 5/5Exceptional variety
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Facilities · 4/5Good facilities
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Crowd / Popularity · 4/5Quite busy
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Current · 2/5Light current
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Surge · 1/5Flat calm
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- VisibilityResearch estimate
- 30m
