RL subs at PD in heavy weather

[Rosencrantz]

Hello!

Two q's:

In the real war diary of U505 I found it writen the boat was able to dive to "A+20m" because one of its torpedo tubes couldn't be closed tight. This lead me to think, why they used the letter A? I assume "A" means the "zero line" = 0 meters. The other possibility is "A" means the keels depth = about 5 meters. Does anyone know the right answer and what was the reason to use a letter?

If the "A" means the zero line, the surface, where does it actually lies if there is a heavy weather? I mean, the "zero line" is movig up and down all the time, so practicaly there is not such a thing like "zero line" actually.
The reason why I'm thinking this "philosophy" is that I wonder, how the rough weather affects for DOOW's actions? If the wave height is let's say 6 - 8 meters, it have to mean the captain can't just give an order: "Make your depth one-three meters", because the boat is unable to follow the motion of the waves. So I assume the boat is driven near surface a bit by bit after the CO's advices, and after the boat has reached the wanted depth, DOOW is just trying to keep the boat in balance.

Does anyone really know if I'm right? Observer for example?

Greetings,

-RC-

[Der Teddy Bar]

A was a code depth that was given to the commanders by BUD/FDU. It was changed through out the war and was used to disguise the u-boat's real depth.

For example, A might be 35, so A+20 was in reality 55.

[Rosencrantz]

Der Teddy Bar wrote:

A was a code depth that was given to the commanders by BUD/FDU. It was changed through out the war and was used to disguise the u-boat's real depth.



Oh, I see... Very logic. Thanks for info. I'm still wondering different procedures in heavy weather. (Maybe because in my ongoing career I haven't been very lucky with weather.)

Many of us seems to dive in storm under a heavy fog. I haven't done this much and actually I have been in collision due to weather just ones in the North Sea and even then I could make it home.
Just wondering, in many documents it's told how they run on surface even in heavy mist, (for example Prien and Kretschmer when looking for a convoy early in 1941 found eachothers boat before the convoy) and I have been thinking what was the reason for this? I think maybe the main reason was communication: In heavy weather the sub likes to dive deeper wich means it's unable to receive any messages via radio. Other possible explinations, like saving the batteries, I consider less valuable. Can anyone confirm these?

-RC-