USS PT 509 - Cornwall & Devon

The USS PT 509 is a proper piece of history, just off the coast and sitting in a surprisingly shallow 12 metres. We love how accessible it is, even for newer divers getting their fins wet on wrecks. This isn't some vast liner, it's a patrol boat, and you can really get a sense of its scale, imagining the cramped quarters. When we're down there, the story of its sinking, ramming a German minesweeper in the fog, really hits home. What's left of the PT 509 is pretty spread out, thanks to that explosion. You’ll weave through scattered sections of hull plating, twisted metal, and machinery, all now completely encrusted with plumose anemones and dead man's fingers. Our favourite part is searching for the smaller artefacts, bits of pottery or tools that sometimes reveal themselves from under a frond of kelp. It’s a great site for photographers who enjoy macro, picking out the blennies and gobies that shelter in every nook and cranny. Visibility can vary, as with any UK site, but on a good day, the light plays beautifully through the remaining structure. It’s not about grand swim-throughs here, it's about connecting with a specific moment in time and seeing how nature reclaims things.

Location
Cornwall & Devon, United Kingdom, Mediterranean & Europe
Coordinates
49.150715, -2.161033
Type
wreck
Maximum Depth
12m

Marine Protected Area: Jersey Coast

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 USS PT 509

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 USS PT 509

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