Also known as: Pathfinder
On 5 September 1914, just weeks into the First World War, HMS Pathfinder made unwanted history as the first major warship ever sunk by a locomotive torpedo fired from a submarine. SM U-21, commanded by Otto Hersing, struck the scout cruiser's forward magazine, and the resulting explosion tore the bow clean off. Of her complement, 259 men were lost. She now rests upright in around 60 metres of water off St Abbs, her hull intact from stern to bridge area but the bow section scattered where the magazine detonated. A designated war grave under the Military Remains Act, she may be visited but not disturbed. The dive is strictly technical territory — deep, cold and demanding — but carries a historical gravity that few wrecks anywhere in the world can equal. Those who descend to her pay their respects to a moment that changed naval warfare forever.
First major warship in history to be sunk by a torpedo fired from a submarine. Struck by a torpedo from SM U-21 (Kapitanleutnant Otto Hersing) off St Abbs. The torpedo hit the forward magazine, causing a catastrophic explosion.
HMS Pathfinder is a warship wreck located off Scottish Borders, United Kingdom at a depth of 62 metres. The vessel was lost due to torpedo in 1914. The wreck is diveable.
HMS Pathfinder lies at 54 to 62 metres depth, Off St Abbs, Berwickshire, North Sea.
HMS Pathfinder was torpedoed on 5 September 1914 during World War I, off Scottish Borders, United Kingdom. 259 people lost their lives.
Diving the HMS Pathfinder is rated technical and is requires technical diving qualifications including decompression procedures. Minimum certification: Trimix or equivalent technical certification. Recommended: Trimix certification.
The best months to dive HMS Pathfinder are May, June, July, August, September. Water temperature ranges from 6°C in winter to 14°C in summer.
HMS Pathfinder is accessed by boat from St Abbs, Scottish Borders, United Kingdom. The wreck is a designated war grave.
| Month | Temp | Visibility | Access | Marine life |
|---|---|---|---|---|
| Jan | 6.0°C | 4.0m | poor | Minimal — winter conditions |
| Feb | 6.5°C | 4.0m | poor | Minimal — winter conditions |
| Mar | 7.0°C | 5.0m | poor | Minimal — winter conditions |
| Apr | 8.0°C | 6.0m | marginal | Moderate — season starting |
| May | 10.0°C | 8.0m | good | Good — soft corals, anemones, wrasse, sponges |
| Jun | 11.5°C | 10.0m | good | Good — soft corals, anemones, wrasse, sponges |
| Jul | 13.0°C | 13.0m | good | Peak — nudibranchs, wrasse, pollack, lobster, dahlia anemones |
| Aug | 14.0°C | 15.0m | good | Peak — nudibranchs, wrasse, pollack, lobster, dahlia anemones |
| Sep | 13.0°C | 12.0m | good | Good — soft corals, anemones, wrasse, sponges |
| Oct | 10.5°C | 7.0m | marginal | Moderate — season ending |
| Nov | 8.5°C | 5.0m | poor | Minimal — winter conditions |
| Dec | 7.0°C | 4.0m | poor | Minimal — winter conditions |
3 evidence records from 3 sources.
Light cruiser. First warship sunk by torpedo from a submarine (SM U-21), 5 September 1914. 259 crew killed.
Designated war grave under Military Remains Act 1986. Technical dive only.
Sits upright on flat seabed at ~62m. Hull intact from stern to bridge. Bow section broken off. Oriented 100/290 degrees. Designated war grave.
Off St Abbs, Berwickshire, North Sea