This is a must watch for anyone those interested in SH4.
This is a documentry of the U.S submarine service, part of the victory at sea series.
Lots of good footage of war patrols and various other stuff, well done and worth it. There is interesting information in this video for example:
50% of the sailors who went through sub training quit.
The submarine service was intergrated as their was a black submariner on board.
After sinking a merchant ship, the crew would rescue the jap merchant men and dress then in dungerees and bring them back to pearl.
IJN destroyers had side mounted propelled depth charges, perhaps maintaining sonar contact while DC.