Proper usage of snorkel

[Gabucino]

Does someone know how real captains recharged their batteries? I mean, hydrophones didn't work (at all?), and the diesel's noise could probably be heard from long range (how long?). Did they come to full stop, to minimize the sound signature (if this mattered at all)? The most ideal time to do this would probably be during night, but that also kills visual detection, especially during storms. But then the u-boot runs deaf and blind, which doesn't seem too healthy to me.

So maybe the only recharging option was when the seas were calm, with no fog, during either day or night...?

(sitting in a XXI right now, trying to play realistically)

[Gerald]

Should you use the snorkel, you may not have as high a speed, then it is possible that you may have problems that result, and that it naturally emits a certain sound, and even a radar signature.

[Freiwillige]

Proper usage of the snorkel was to reduce speed to about 5 knots or slower obviously the slower you go the less wake left by the device. After all these boats still had assigned patrol zones to reach within a designated period.

Once darkness fell they would still at times come to the surface although at great risk.

The Snorkel wasn't fool proof but it did increase the odds of getting through to your zone in one piece.

[LGN1]

Here's some interesting information about the topic:

http://www.uboatarchive.net/BDUOrder2.htm

[Gabucino]

Thanks!