CAROLINA THORNDEN - Scapa Flow, Orkney
The *Carolina Thornden* is a blockship, deliberately sunk in 1940 to protect Scapa Flow. It’s a shallow dive, barely 2m deep, making it an excellent option for newer divers or those looking for an extended shallow exploration. We love how accessible it is, sitting upright and mostly intact on the seabed, practically inviting you to swim through its cavernous holds. We usually jump in at high slack water to avoid any surface chop, and often take our time simply finning along the deck, peering into the exposed engine room. You'll find a surprising amount of soft coral growing on the bulkheads, and often schools of juvenile coalfish darting between the frames. It’s a great spot for macro photography too; we've found nudibranchs and squat lobsters tucked away in crevices. This isn't a dive for big pelagics, but for an intimate look at a piece of wartime history reclaimed by the sea, it’s a brilliant choice.
- Location
- Scapa Flow, Orkney, United Kingdom, Mediterranean & Europe
- Coordinates
- 58.840140, -2.901617
- Type
- wreck
- Maximum Depth
- 2m
Wreck History - CAROLINA THORNDEN
- Year Sunk
- 1942
- Vessel Type
- tanker
- Cause
- scuttled
The Carolina Thorden has a history intrinsically linked to the defence of Great Britain during World War II. A steel single-screw motor tanker built in 1938, she was requisitioned for a critical purpose. On April 8, 1942, she was deliberately sunk as a blockship in Scapa Flow, the Royal Navy's primary wartime anchorage in the Orkney Islands. Her role was to obstruct one of the eastern channels, strengthening the formidable defences designed to prevent enemy submarines from entering the Flow.
Resting in just 2 metres of water, the Carolina Thorden is an ideal site for snorkelers and trainee divers. While over 80 years of North Sea storms have taken their toll, her immense steel hull is still clearly visible, broken and scattered across the seabed. Exploring the wreckage provides a tangible connection to the past, a reminder of the strategic importance of Scapa Flow. Divers can trace the vessel's remains and appreciate its final, silent duty in one of the world's most historic naval harbours.
Marine Protected Area: Switha
Best Time to Dive in Scapa Flow, Orkney
The warmest water temperatures in Scapa Flow, Orkney occur in January, averaging 8.4°C. The coolest conditions are in December at 8.4°C.
Monthly Water Temperatures
- January: 8.4°C (air: 5.5°C)
- February: 8.4°C (air: 5.3°C)
- March: 8.4°C (air: 5.9°C)
- April: 8.4°C (air: 6.8°C)
- May: 8.4°C (air: 9.7°C)
- June: 8.4°C (air: 12.4°C)
- July: 8.4°C (air: 13.2°C)
- August: 8.4°C (air: 13.7°C)
- September: 8.4°C (air: 12.7°C)
- October: 8.4°C (air: 10.2°C)
- November: 8.4°C (air: 8.0°C)
- December: 8.4°C (air: 5.8°C)
Nearby Dive Sites in Scapa Flow, Orkney
- 090 - 26m (wreck)
- AASE - 60m (wreck)
- ABERDEEN CITY - 5m (wreck)
- AC6 - 5m (wreck)
- ACHILLES - 32m (wreck)
- ACTIVE - 42m (wreck)
- Aith Baa (reef)
- ALABAMA - 12m (wreck)
- ALCORA (POSSIBLY) - 40m (wreck)
- ALMERIA - 5m (wreck)
- ANDALINA - 8m (wreck)
- ANDRIAS - 27m (wreck)
- ANVERS - 52m (wreck)
- AORANGI - 5m (wreck)
- ARCADIA - 30m (wreck)
Nearest Dive Centres to CAROLINA THORNDEN
Marine Life in Scapa Flow, Orkney
Home to 155 recorded species including 63 reef fish, 17 whales & dolphins, 12 sharks & rays, 11 crabs & lobsters, 11 other, 10 seagrass & algae.
Notable Species
- Protestant (Clupea harengus) - Reef Fish
- Haddock (Melanogrammus aeglefinus) - Reef Fish
- Cowfish (Tursiops truncatus) - Whales & Dolphins
- whiting (Merlangius merlangus) - Reef Fish
- dab (Limanda limanda) - Reef Fish
- harbour porpoise (Phocoena phocoena) - Whales & Dolphins
- grey gurnard (Eutrigla gurnardus) - Reef Fish
- long rough dab (Hippoglossoides platessoides) - Reef Fish
- dogfish (Scyliorhinus canicula) - Sharks & Rays
- Atlantic cod (Gadus morhua) - Reef Fish
- poor cod (Trisopterus minutus) - Reef Fish
- sprat (Sprattus sprattus) - Reef Fish
- Common minke whale (Balaenoptera acutorostrata) - Whales & Dolphins
- Split (Scomber scombrus) - Reef Fish
- Norway Lobster (Nephrops norvegicus) - Crabs & Lobsters
- Common dragonet (Callionymus lyra) - Reef Fish
- lesser argentine (Argentina sphyraena) - Reef Fish
- white-beaked dolphin (Lagenorhynchus albirostris) - Whales & Dolphins
- Common sea star (Asterias rubens) - Starfish
- Soldier (Chelidonichthys cuculus) - Reef Fish
Recommended Packing List for CAROLINA THORNDEN
Based on average water temperature of 8.4°C.
- Drysuit - water at 8°C demands a drysuit with thermal undergarments
- Hood & Gloves (7mm+) - critical to prevent heat loss
- 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