Wreck of U-18 (Probably) - Scapa Flow, Orkney

The HMS M28, lying within the protected waters of Alonissos Marine Park, offers a genuinely distinctive dive. We love that it's an M15-class monitor, a proper historical vessel from 1915, not just some scattered debris. Dropping down, the sheer scale of the wreck starts to emerge from the blue. You can make out the gun mounts and the hull’s basic structure, all now draped in a thick carpet of sponges and hydroids. Schools of damselfish shimmer around the superstructure, darting in and out of the shadows. Our favourite time to dive the M28 is in the morning, when the sun is higher, because it really illuminates the upper sections and brings out the colours of the encrusting life. Look closely in the nooks and crannies – we’ve seen moray eels peeking out and sometimes a scorpionfish camouflaged on the deck. It’s a site that rewards a slow, deliberate exploration, perfect for divers who appreciate history blended with healthy marine growth. Just be mindful of the currents, which can pick up at times, especially around the exposed sections of the wreck.

Location
Scapa Flow, Orkney, United Kingdom, Mediterranean & Europe
Coordinates
58.702145, -2.801386
Type
wreck

Marine Protected Area: Pentland Firth Islands

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

Nearest Dive Centres to Wreck of U-18 (Probably)

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

Recommended Packing List for Wreck of U-18 (Probably)

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