Upholder's 1942 disappearance remains unresolved in this account, without an identified wreck to settle the competing explanations. Air attack, a minefield, and an encounter with convoy escorts are possibilities, including air damage followed by a fatal surface attack. A reported sighting would count against the minefield theory if reliable, but it rests on one source. The boat had been ordered to meet two other submarines for an attack on a convoy, leaving open the possibility that she encountered its escorts on the way. Many anti-submarine attacks occurred in the area, and wartime crews often fired on uncertain contacts because missing a real submarine seemed the greater risk. Mistaken sightings of dolphins illustrate why an attack report alone cannot reliably identify the cause of Upholder's loss.
Notable Point · 1:34:58-1:38:17
Why Upholder's loss remains difficult to explain
Competing accounts of Upholder's disappearance depend on uncertain sightings and attack reports, including contacts that may never have been submarines.