Naval Historywith Dr. Alex

Q&A · 4:42:49-4:44:22

HMS Venturer made the only recorded submerged-on-submerged kill

The February 1945 sinking of U-864 off Norway remains the only publicly recorded case of one submerged submarine deliberately sinking another submerged submarine.

HMS VenturerRoyal NavySubmarine WarfareU-864World War II
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Question

What was the deepest submarine-on-submarine combat on record?

Short answer

HMS Venturer's submerged sinking of U-864 in 1945 is the only publicly recorded submerged-on-submerged kill.

Notes

Earlier cases involved one submarine being on the surface. HMS Venturer attacked U-864 while both boats were submerged off Norway on 9 February 1945. That geometry required predicting a target moving in three dimensions rather than firing at a surfaced hull. It is the only deliberate case available in the public record, though later secret patrols leave open the possibility of unrecorded encounters.