Old Issac’s - Grand Cayman
Roca Peligrosa, or Danger Rock, sounds a bit intimidating, doesn't it? But we've always found it to be more exciting than dangerous, an exposed pinnacle poking out of the Caribbean just south of the Catalina Islands. We love this site for its raw energy; the surge here is almost constant, rocking you gently back and forth as you trace the contours of the rock face. Our favourite way to dive it is to descend quickly, hugging the rock as it slopes down to a modest 20 metres. You'll often find big schools of red snapper and brassy grunt hanging in the current, almost shimmering as the light filters through. Keep an eye out for blennies – the Panamanian worm blenny and Hancock's blenny are particularly good finds tucked into crevices. While the visibility can be a bit variable, averaging around 11 metres, the sheer volume of fish makes up for it. This isn't a beginner's site; the surge and occasional stronger currents mean you need to be comfortable in the water, but for divers who enjoy a bit of dynamism, it's a real treat. We once had an olive ridley sea turtle cruise by, completely unfazed by the movement, which was a real highlight.
- Location
- Grand Cayman, Cayman Islands, Caribbean
- Coordinates
- 19.295200, -81.089500
- Type
- reef
Marine Protected Area: Radio Mast - Sand Bluff (Grand Cayman)
Best Time to Dive in Grand Cayman
The warmest water temperatures in Grand Cayman occur in September, averaging 30.4°C. The coolest conditions are in February at 26.9°C.
Monthly Water Temperatures
- January: 27.3°C
- February: 26.9°C
- March: 27.0°C
- April: 27.7°C
- May: 28.7°C
- June: 29.2°C
- July: 29.8°C
- August: 30.3°C
- September: 30.4°C
- October: 30.0°C
- November: 29.0°C
- December: 28.0°C
Nearby Dive Sites in Grand Cayman
- Anchor Point (cenote)
- Anchor Point (wall)
- Angelfish Reef - Grand Cayman (reef)
- Angelfish Reef - Grand Cayman (reef)
- Aquarium - Grand Cayman (reef)
- Aquarium - Grand Cayman (wall)
- Armchair Reef (reef)
- Armchair Reef (reef)
- Babylon, Cayman (reef)
- Babylon, Cayman (reef)
- Balboa (Wreck) (wreck)
- Balboa (Wreck) (reef)
- Bear’s Paw (reef)
- Bear’s Paw (wall)
- Big Dipper (reef)
Nearest Dive Centres to Old Issac’s
- Atlantis Dive Center
- Divers Down - PADI
- Divers Supply
- Divetech - PADI
- Diving Center - SSI, PADI, CMAS, NAUI, FEDAS, ACUC
- Don Foster's Dive Cayman, Ltd. - ["PADI"]
Marine Life in Grand Cayman
Home to 332 recorded species including 276 reef fish, 30 hard corals, 5 other, 5 seagrass & algae, 4 whales & dolphins, 4 sharks & rays.
Notable Species
- Elkhorn coral (Acropora palmata) - Hard Corals
- Massive Starlet Coral (Siderastrea siderea) - Hard Corals
- Mustard hill coral (Porites astreoides) - Hard Corals
- Gutong (Scarus iseri) - Reef Fish
- Dark Green Parrotfish (Sparisoma viride) - Reef Fish
- Blue Doctor (Acanthurus coeruleus) - Reef Fish
- Gutong (Sparisoma aurofrenatum) - Reef Fish
- French grunt (Haemulon flavolineatum) - Reef Fish
- Great star coral (Montastraea cavernosa) - Hard Corals
- Barber (Acanthurus bahianus) - Reef Fish
- Finger Coral (Porites porites) - Hard Corals
- Butterfly (Chaetodon capistratus) - Reef Fish
- Schoolmaster (Lutjanus apodus) - Reef Fish
- Grunt (Haemulon plumierii) - Reef Fish
- Lettuce Coral (Agaricia agaricites) - Hard Corals
- Bluestriped Grunt (Haemulon sciurus) - Reef Fish
- Sheephead (Microspathodon chrysurus) - Reef Fish
- Sammy Johnson (Scarus taeniopterus) - Reef Fish
- Cola (Ocyurus chrysurus) - Reef Fish
- Graysby (Cephalopholis cruentata) - Reef Fish
Recommended Packing List for Old Issac’s
Based on average water temperature of 28.7°C, currents 9 cm/s.
- Shorty or Rashguard - warm 29°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