Stealth Catch 22
 

In a VIIB going deep to avoid detection, silent procedure slows the boat to two knots. But to eliminate this buoyancy thing one has to run at three knots to keep from rising. Three knots alerts hunters.
The Reduced Positive Buoyancy Mod in JSGME overwrites files modded by the Depth Charge Shake Mod I am enjoying.
I tried loading them in different sequence, but still feel that something is getting screwed in the simulation. The damage aspect in particular. I had collossal damage from depth bomb attack, saved the boat, but showed 100% hull integrity. ?
So if I want to do without the shake rattle and roll, I can load Less Buoy but not Depth Charge Shake. But if I have to be tossed about to like it, then I live with this speed adjustment to keep from rising. Where did this come from? I have always read, and heard from certain uboat commander comments, that a boat would descend rather than rise if a modicum of speed wasn't kept up.
Reverie

If the buoyancy gets you deeper or higher should depend on how deep you actually are. Higher depths mean higher water pressure from above which would drive you deeper. Holding depth means that the depth rudders are set to give you some uplift against that. It's similiar to a plane, which too needs forward motion to make use of its wings ;)

What I don't understand quite well is why you get bounce upwards when e.g. at periscope depth while standing still. Shouldn't the crew be able to let some more water into the flooding tanks to make the sub a bit more heavier ?

Realistic DCs won't shake you unless they are real close. Close enough to cause damage. (15 meters, depending on depth).

The deeper you go, the less effective is the DC explosion due to pressure. :D

They could do that, in theory, but it is an extremely delicate balancing act. In fact, just having one person move from the stern compartment to the bow compartment would make the bow heavy enough to point down and upset the trim.

It can be done in modern subs, with computer controlled ballast systems, but really it wouldn't be practical in a sub like a Type VII. You need some headway to make the planes effective to overcome any inaccuracies in trimming the boat.

I find that setting your depth about 2-3m below PD gets you to PD at 2kt. I rarely have problems with depth keeping as long as you remember to do this.

That's what I do too, but if you forget about it and your conning tower already sticks out of the surface it can be too late :D

A bit of a double edged sword really, because the deeper your u-boat goes the more vulnerable the pressure hull becomes, therefore the weaker explosions can still be fatal.

Nemo

It's also very noisy.

As for the sub rising or sinking, I prefer NYGM's balance model, called the 'Anti-Hummingbird Mod', not only because the boat sinks at low speeds or full stop, but because it's not just two meters; it keeps sinking until you do something about it.

This was a lot of fun in Aces Of The Deep. You would be at Silent Running for a while, and then your chief would suddenly say "Herr Kaleun, we cannot maintain depth unless we run the pumps!"

Sounds funny ;)
Though it would be good if you could set the depth rudders manually to stop the boat from sinking further. This would work at least for the case of silent running while you still would have to be careful at full stop.

With NYGM to run under 100 rpm you need to go down to 1 knot, but the sinking rate is very slow, and when you make a small dash when safe takes you back to your depth.

I used Depth Charge Shake mod at one time but removed it. At the time I did find a Reduced Positive Buoyancy mod specific to Depth Charge Shake. The author of Depth Charge Shake had this as a mini-mod; check his dowload site and you might find it.