Your're right about the surface. That was not the problem.
But keep the boat steady underwater was very difficult. In theory it was absolutly possible to keep the boat in ine depth even without making one knot. But in reality things look different. Every shift of weight, from a fired torpedo to man who changes his position inside the boat had to be exactly counterflooded by the LI. Just imagine the boat balancing on one of your fingertips. That ist the behaviour of an U-Boat underwater. One little divergense in you calculated flooding and the boat wents down or goes up. Sure, the Li did that exact calculation at the beginning of every day, factoring the use of diesel, water etc. into this. (Well exact is the wrong word here. Should be as exact as it was possible ;) ) Wich become quite complicated if you think about that diesel and drinking-water has another density that the salt-water.Not to mention food and other things used up. But when the day went on more of it was used of course. And there maybe they shot some torpedes before diving. Considerating that exact calculation of the quantity of salt-water you need to flood aganist in seconds is just impossible. How did they keep the boat in balance then ? Right, guessing and planesmen. But to get the planes working you need speed. The more inaccurate your calculation is, the more you need. So if you had an good LI and you had to dive right after he got his calculation finished maybe then it would have been possible to steady the boat with one knot. Maybe.....

My issues with this "feature", if it is one, is that even if the boat was very difficult to keep trim, I'd imagine the planesman and the other guys would still correct it to match what the Captain ordered.

So instead of just constantly sinking to crush depth without so much as 'boo', they'd be correcting - and you'd simply get imprecise depth (planing up and down to keep within 5M or so of the target depth).

Is there no "difficulty setting" which would allow you to turn off the crew moral or skill leveling features

JD

Precise depthkeeping like holding periscope depth at 0 kts? Agreed that is realistically not going to happen. You typically run periscope depth as slightly heavy so that you have to plane up to your intended depth. This way in case of any mistake or lack of speed you drop instead of broach.

However gross depthkeeping in a +/-20m window? That should be accomplished ably by buoyancy and ballast control only. It might be messy, taking a lot of compressed air and bouncing up and down as the crew balances and adjusts constantly but runaway uncontrollable sinking? Please.

Why would more speed for planing be required as depth increases? I know the hull contracts lowering buoyancy but that's why the crew compensates with a little more positive buoyancy. It looks like a simple model coded by UBI to make reasonable near-surface behavior but no one bothered to test to see the behavior become ridiculous as depth increases.

Acutally though, from what i noticed its fine tell around 200 meters. I'ts like the game reachs a cutoff point and goes, "Ok tahts it, i give up on trim" Although i didn't test the 7A. In SH4, this cutoff point was 600 feet, or 183 meters. Few noticed it back then, but i did when testing thick skinned boats like the balao or tench class.

I was working on it for a little while, but gave up on it. This issuue came up in Sh4, and wasn't REALLY noticed since players would rarely be forced to go that deep. I did however, and i knew any uboat mod would have to face it sooner or later. I think the devs knew about it because in the CFG file they have max depth listed as 200 meters accross all boats except the 7B. For some reason that one was all different.

Long story short, if this bug is indeed behaving how i think it is (IE. like it did in SH4, you'd better hope not), your max depth is going to be limited to 200 meters or your going to lose control of the boat. You'll have 3 options. Flank speed, blow ballast, or crush.

If their some coefficient for how much buoyancy is lost per depth unit? Is this hardcoded behavior? This isn't the UBI devs using the "Type 21" compartment theft workaround that modders first thought up is it?

I mean, what's proper behavior if you were writing the code from scratch? Would there be a static negative buoyancy fraction with crew-skill-based random fluctuation or God-forbid, player control?

Hi Ducimas, it looks like it's the later, I had to blow balast and go to flank speed, regained control at about 4o metres. I will say it makes dodging destroyers "much" more interesting i.e. you can't just leave the boat at 150 metres and go off to make a cup of tea!!:arrgh!:

The deeper you go, the most weight is acting on the submarine since you have water not only all around but pressing from all above. As you go deeper, you must increasing buoyancy to control rate of descend.

There is limit. Once tanks are filled with air and it is not enough to rise, all you can do to rise is use diving planes and crank up engines.

Most subs never go below the point where with ballasts fill of air they need to use engines to go up.

All modern subs use engines and dive planes with neutral buoyancy to rise and dive. Tanks are only used for emergency and when very close to periscope or surface. The ship is brought to level then tanks are used.