JEANNE MARIE - Cornwall & Devon

The Jeanne Marie, a French steamer sunk by a U-boat in 1918, lies deep at 53 metres. We think this depth makes her a truly rewarding dive for experienced technical divers, and she’s one of our favourite deep wrecks off the Cornish coast. You’re descending into proper historical theatre here, the ship’s large profile emerging from the gloom, often with visibility that feels like thick soup at the surface but can open up beautifully down below. The wreck itself is largely intact, with a huge triple-expansion engine standing proud amidships, a real magnet for light-seeking fish. We love exploring the bow, which is often riddled with conger eels – some of them absolute monsters, thick as a diver's thigh. Keep an eye out for dogfish tucked into crevices and the occasional solitary ling patrolling the deeper sections. It’s a dark dive, even on a sunny day, so good lighting is non-negotiable. Dive this one on slack water, and be ready for a longer decompression, but the silence and the sheer scale of the Jeanne Marie are utterly worth it.

Location
Cornwall & Devon, United Kingdom, Mediterranean & Europe
Coordinates
49.338184, -2.330700
Type
wreck
Maximum Depth
53m

Marine Protected Area: Gouliot Caves and Headland, Sark

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 JEANNE MARIE

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 JEANNE MARIE

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