HMSM A3 - Cornwall & Devon

The A3 holds a special place in British diving history, a poignant story beneath the waves just off the Eddystone Lighthouse. We’ve always been drawn to wrecks with a bit of drama, and this submarine certainly delivers. Sunk not once, but twice, first by collision then by gunfire, she’s now a proper dive at 36 metres. Dropping down, the first thing you notice is her sheer size, 30 metres of history. She lies upright, largely intact, and you can still pick out the conning tower and hatches, even some of the torpedo tubes. What we love about the A3 is how nature has reclaimed her; the steel plates are thick with dead man's fingers, and huge plumose anemones flower in the current. Look closely inside the torpedo tubes – often you’ll spot conger eels peeking out, or even a sleepy dogfish tucked away. It's a proper atmospheric dive, best done on a slack tide to really appreciate her lines, otherwise, that current can certainly make you work for it. This is a dive for those who appreciate maritime history and a bit of a deeper challenge, a true piece of naval heritage given back to the sea.

Location
Cornwall & Devon, United Kingdom, Mediterranean & Europe
Coordinates
50.523735, -2.188583
Type
wreck
Maximum Depth
36m

Marine Protected Area: Studland to Portland

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 HMSM A3

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 HMSM A3

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