[PepsiCan]

Hi

What also did not help is the culture. US subs were supposed to be used as support for the surface fleet. The original doctrine was that subs would sail together with the surface fleet to engage the enemy (hence the name fleet submarine). Engaging warships and doing recon missions were the main tasks and attacks on merchants should happen according to the price rules (surface, warn vessel to abandon ship, sink it, rescue survivors).

Because the submarine arm still needed to establish itself within the navy as a weapon of importance (there were serious doubts as to whether subs could actually sail with the fleet due to their slow surface speed) and because US doctrine assumed that asdic would make it very difficult to break through a destroyer screen, any actions against standard rules and discipline were penalised rather harshly. So, this cemented a culture of carrying out orders strictly and being very cautious when engaging the 'enemy' during exercises. It meant captains showed very little initiative and were risk averse.

When war broke out, Nimitz ordered unrestricted sub warfare. It required boats to operate deep in enemy territory no longer at arms length of submarine command. What you need in those circumstances is a commander that can assess the tactical situation and act at his own discretion. Exactly the opposite type of commander that the US navy had been breading over the past two decades.

Of course it wasn't only that. Early on in the war, the US navy decided to use the broken japanese code to guide subs to japanese convoys. However, these setup rendez vous didn't always work due to navigational errors etc. It was only towards the end of 1943 that the US navy decided to have subs wait at choke points in the convoy routes. At that point the 'new' command culture came together with a sound strategy and working ammunition. A year later, the Japanese merchant navy was essentially whiped out and the US navy had succeeded in doing to Japan what the German navy failed to do to Great Britain.