HMSM UPSTART - Cornwall & Devon

The HMSM Upstart is one of those wrecks we keep coming back to. Sitting upright at 37 metres, she’s an easy dive on a calm day, though that depth means some current can really make it a workout. Built in 1942, this U-class submarine was scuttled in 1957, so she’s been down there a while and the sea has really claimed her. We love finning along her deck, spotting the periscope tubes and the outline of her conning tower. The bow torpedo tubes are a particular favourite – you can usually see conger eels peering out, their thick bodies disappearing back into the dark. Look closely for dogfish eggs tucked into crevices and always keep an eye out for curious seals. If you hit it right, with good visibility and slack water, it’s a genuinely atmospheric dive, a real window into naval history and the power of the ocean to reclaim what’s hers. This isn't a site for beginners; that depth and the potential for current mean you want to be comfortable with your diving.

Location
Cornwall & Devon, United Kingdom, Mediterranean & Europe
Coordinates
50.506893, -1.546573
Type
wreck
Maximum Depth
37m

Marine Protected Area: Tennyson

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 UPSTART

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 UPSTART

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