MERDIS - Cornwall & Devon

We love the Merdis. This wreck, a casualty of a German U-boat in 1917, now rests upright on the seabed at 35m. Dropping down, the first thing that hits you is the sheer scale. It's a big ship, still largely intact, and you can swim through the holds, imagining the cargo she once carried. The light filters down, illuminating clouds of juvenile pollock that swirl through the superstructure. Look closer, and you’ll find conger eels peering from every dark recess, their heads like knobbly fists, and the occasional dogfish tucked into the sand nearby. Our favourite moment is always finning past the stern, where the prop shaft and rudder are still clearly visible, encrusted in dead man's fingers. It's a dive that rewards slow exploration, allowing you to really soak in the history and the way the ocean has reclaimed it. Visibility can be a bit of a lottery, as it often is off the Cornish coast, but when it’s good, the Merdis is simply fantastic. Definitely one for experienced divers comfortable with deeper wrecks and the occasional current.

Location
Cornwall & Devon, United Kingdom, Mediterranean & Europe
Coordinates
50.403385, -1.469463
Type
wreck
Maximum Depth
35m

Marine Protected Area: Wight-Barfleur Reef

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 MERDIS

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 MERDIS

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