HM submarine A3
Protected Area
Studland to Portland
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) - HM submarine A3 offers some of Cornwall & Devon's richest wreck diving. Water ranges 10-18°C, warmest July, August, September.
The HM submarine A3 is a real treat for anyone who loves a bit of history with their diving. This isn't some broken-up pile of metal; she sits upright and largely intact at 32 metres, a proper time capsule. Dropping down, you'll see her shape emerge from the gloom, long and slender, almost exactly as she looked when she sank in 1912 after a collision. We particularly love the feeling of swimming along her deck, imagining the crew on board. While the conning tower hatch is gone, and a few windows are open, the pressure hull is remarkably preserved. You can’t penetrate, of course, but just seeing the torpedo tubes still in place, peering into those open spaces, gives you a shiver. It’s dark down there, even on a sunny day, so good lights are essential to pick out the details and the marine life that has made her home. Expect to find plenty of crabs tucked into crevices, some respectable lobsters under the hull, and often a decent sized conger eel or two peeking out. It’s a site that really makes you think, a sombre reminder of naval history, and our pick for anyone who appreciates the quiet dignity of a well-preserved wreck.
Typical HM submarine A3 Dive Profile
Illustrative profile based on site depth and type. Actual dive profiles vary - always follow your dive computer and training.
Safety Notes
Deep dive (32m) - monitor air consumption closely. Advanced certification recommended.
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.
Nearest Dive Centres to HM submarine A3
Dive shops near HM submarine A3
Dive Beyond Limited
Divers Down
Old Harbour Dive Centre
Mayim Mermaid Academy
Dorset Diving Services
TAL Scuba Ltd.
Reviews for HM submarine A3
Conditions
Ocean conditions, forecast and tides for HM submarine A3
HM submarine A3 Ocean Conditions
Monthly averages for HM submarine A3, 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
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