PLM 4
Protected Area
Dolphin Head Highly Protected Marine Area
Why dive here
With 176+ marine species recorded in the area - including blue sharks, dolphins, dwarf minke whales, humpback whales and ocean sunfish (mola mola) - PLM 4 offers some of Cornwall & Devon's richest wreck diving. Water ranges 10-18°C, warmest July, August, September.
PLM 4, a steamship sunk in 1917, lies at 49 meters off the Cornish coast. She's a good deep dive, though currents can be tricky, so we always check the tides before heading out. The wreck itself is in decent shape, broken in places but still very much a ship. You can trace her lines and get a sense of her original form, which is always satisfying on a wreck this old. Expect to see plenty of local colour – conger eels often peek from the darker nooks, and we’ve spotted various crabs scuttling across the plates. It's a dive for those who appreciate history and don't mind the chill of the Atlantic.
Typical PLM 4 Dive Profile
Illustrative profile based on site depth and type. Actual dive profiles vary - always follow your dive computer and training.
Safety Notes
Maximum depth 49m exceeds recreational limits (40m). Technical diving certification and equipment required.
Wreck site - avoid penetration without wreck diving certification. Watch for sharp metal and entanglement hazards.
Always perform a 3-minute safety stop at 5m before surfacing.
Reviews for PLM 4
Conditions
Ocean conditions, forecast and tides for PLM 4
PLM 4 Ocean Conditions
Monthly averages for PLM 4, sourced from Open-Meteo marine data - nearest station: Open-Meteo marine grid (50.44, -2.73) (3km away)
October Averages
Sea Temperature
17°C
62°F · Range: 15.1–17.5°C
Air Temperature
13°C
56°F
Wind Speed
8.14 m/s
15.8 knots
Atmospheric Pressure
1011 hPa
Based on 4 years of monitoring data · Data sources: Open-Meteo marine data
Plan & book
Ways to dive Cornwall & Devon, from day trips to liveaboards.
Day trips & courses
via GetYourGuideGuided dives, courses and snorkel trips with instant booking.
Find dive trips in Cornwall & DevonPlaces to stay
via Booking.comHotels and dive resorts near Cornwall & Devon.
Search stays in Cornwall & DevonDive insurance
Most travel insurance excludes or limits scuba. Check what you need before you go.
Dive insurance explainedPartner links: we may earn a commission if you book, at no extra cost to you. How we make money
Where to Stay near PLM 4
Prices from Booking.com. We may earn a commission at no extra cost to you.