This was an aerial night mining mission involving 24 planes from the 6th Bomb Group:
Two days later another mining mission was flown. This time the “drop area” was Mine Fields “B” and “F” in the Bingo Sea just north of Shikoku Island. Twenty-five airplanes were airborne – one lost an engine after takeoff and was forced to jettison its loan and return early – and planted 201 mines in the Inland Sea. These mines were largely 2,000 pounders with a few 1,000 pounders for shallow water. It was a night operation with mines laid by radar and the radarscope showed excellent results. No aircraft were damaged and all returned without mishap.
[Pirate’s Log, p. 41]
20th AF Mission 150