HM SUBMARINE NO 1 - Cornwall & Devon

We really love a wreck with a story, and HM Submarine No 1 certainly delivers. This isn’t some grand battleship, but a slice of naval history – the Royal Navy's very first submarine, lost in 1913 while under tow to the breakers. Dropping down to 59 metres, the visibility can be tricky here in the English Channel, often a milky green, so good lights are essential. But once you break through, the wreck emerges, surprisingly intact for its age. At just under 20 metres long, you can trace its full outline. We always try to imagine it in its original form, a pioneering machine. Now, it’s a living reef. Expect plenty of squat lobsters tucked into every crevice, big conger eels lurking in the deeper sections, and sometimes, the surprising flash of a John Dory against the hull. The currents can be serious, so this is definitely one for experienced technical divers. We’d suggest diving this one on a slack tide, aiming for the hour either side of high or low water to make the most of your bottom time exploring a truly unique piece of diving history.

Location
Cornwall & Devon, United Kingdom, Mediterranean & Europe
Coordinates
50.176983, -4.169465
Type
wreck
Maximum Depth
59m

Marine Protected Area: Rame Head

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 HM SUBMARINE NO 1

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 HM SUBMARINE NO 1

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