CAMBRIAN - Cornwall & Devon

The Cambrian isn't about deep diving; it's about history you can touch, right in the shallows. Sunk during the Dunkirk evacuation in 1940, this former trawler turned naval auxiliary vessel now lies broken but still recognisable in just four metres of water. We love popping down here on a calm day, especially with a bit of sun – the light play through the kelp can be incredible. You’ll find the bow and stern mostly intact, with the midships section more collapsed. Look for the engine block, still pretty solid, and the boiler, which often has conger eels tucked inside. It’s our favourite kind of shallow wreck: easily accessible, full of character, and teeming with life that’s made it home. Shoals of bib dart through the broken plates, spider crabs scuttle across the rusty framework, and we’ve often spotted dogfish resting in the sand nearby. If you’re into underwater photography, the Cambrian offers fantastic wide-angle opportunities, especially when the visibility is good, which averages around 5-10 metres here. Aim for a slack tide an hour or so before high water for the best conditions and minimal current. It's a perfect site for newer divers looking for their first wreck experience or for snorkelers who want more than just reef.

Location
Cornwall & Devon, United Kingdom, Mediterranean & Europe
Coordinates
50.741768, -1.056617
Type
wreck
Maximum Depth
4m

Wreck History - CAMBRIAN

Year Sunk
1940
Vessel Type
fishing vessel
Cause
mine

Before her military career, HMS Cambrian began life in 1924 as the steam trawler Lord Derby, built by Cochrane & Sons in Selby. She served in the fishing fleets under several different names, including Ocean Knight and Stella Procyon. With the outbreak of the Second World War in 1939, she was requisitioned by the Admiralty for naval service, armed, and commissioned as HMS Cambrian, tasked with the vital role of a boom defence vessel.

Her naval career was short-lived. On May 30, 1940, while on patrol, HMS Cambrian struck a German-laid mine. The explosion was catastrophic, and the vessel sank quickly, becoming an early casualty of the war at sea. Her loss highlighted the constant danger faced by even the smallest support vessels of the Royal Navy.

Today, the wreck of HMS Cambrian rests in just 4 metres of water, making it a fantastic and highly accessible dive for all experience levels. The shallow depth ensures excellent light and long bottom times. While the mine explosion and subsequent years underwater have left the wreck well broken, divers can easily identify key features like her boiler, parts of the triple-expansion engine, and scattered hull plating. It's a perfect site for a relaxed second dive, underwater photography, or for new divers to experience their first wreck.

Marine Protected Area: St Helen's Duver & Priory Wood

Best Time to Dive in Cornwall & Devon

The warmest water temperatures in Cornwall & Devon occur in January, averaging 9.6°C. The coolest conditions are in December at 9.6°C.

Monthly Water Temperatures

  • January: 9.6°C (air: 7.3°C)
  • February: 9.6°C (air: 8.4°C)
  • March: 9.6°C (air: 8.6°C)
  • April: 9.6°C (air: 10.1°C)
  • May: 9.6°C (air: 12.6°C)
  • June: 9.6°C (air: 15.2°C)
  • July: 9.6°C (air: 16.6°C)
  • August: 9.6°C (air: 17.1°C)
  • September: 9.6°C (air: 15.9°C)
  • October: 9.6°C (air: 13.5°C)
  • November: 9.6°C (air: 10.7°C)
  • December: 9.6°C (air: 8.7°C)

Nearby Dive Sites in Cornwall & Devon

Nearest Dive Centres to CAMBRIAN

Marine Life in Cornwall & Devon

Home to 192 recorded species including 93 reef fish, 18 sharks & rays, 13 whales & dolphins, 11 crabs & lobsters, 11 other, 10 seagrass & algae.

Notable Species

Recommended Packing List for CAMBRIAN

Based on average water temperature of 9.6°C.

  • Drysuit - water at 10°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