Diving system seems weird

[THE_MASK]

I only use the negative tank and dive planes for depth control (thats why there are 2 wheels for blowing and flooding the negative tank without having to blow the main tanks) . I only blow the main tanks if i want to completely surface . So as soon as i get to the surface i flood the negative tank for when i need to crash dive . If i want to dive i flood the main tank and when i have reached the desired depth i blow the negative tank . If i need to dive quickly i will flood the negative tank again and then blow the negative tank when i have reached the desired depth .

[AS]

I just took the time for crash dive exercise (note that I played alone):

10m (Tower disappears in the water): 28-30 Sec. (this is absolutely accurate historically)

50m: About 1:10

100m: About 1:58

150m: 2:48

With an EMPTY negative tank (German: Untertriebszelle) it takes about 1min and 40 seconds to dive at all! So the negative tank MUST be filled when on Surface!

At greater depths the boat realistically takes on water, so you must take this into account when moving slowly: the boat will tend to sink bit by bit. I will try and blow the main Ballast tanks A TINY BIT before going real Deep to compensate for flooding. (Trying all these things is so much fun I cannot believe a "game" actually let´s me do all this fancy "U-Boat stuff". So far I didn´t fire a single Torpedo, I just love to OPERATE "Das Boot"!)

Maybe the compressed air-behavior is correct, considering the fact that you only Need to get rid of SOME water to make the boat raise. However, the surfacing Speed is way to slow I´m sure.

[AS]

Originally Posted by sober

I only use the negative tank and dive planes for depth control

In reality they had so called trimming and adjusting tanks ("Regelzellen" in German) which were used to compensate for weight changes due to food and fuel-consumption, torpedoes etc. That´s why they had to "balance and Level" the boat every day. The negative tank (German: Untertriebszelle) was just there to speed up diving. It was blown (=emptied) fairly quickly after diving.

Physically interesting fact: When they went Deep, they FILLED the negative tank a little bit to KEEP the U-Boat ballanced. The reason for this: the deeper a Sub dives, the more it is "squeezed" so it loses volume. Less volume means less water replacement. This will Change the raise-sink tendency. So they had to make the boat heavier in great depths to compensate for that.

Another effect, which has similar physics: in very calm weather they could "hang" the U-Boat at periscope Depth without engines (=fully stopped). Certainly, a ZERO balance is not possible, but the periscope shaft itself changed the U-Boat´s replacement when it went a bit deeper or raised a bit, so this tiny little bit was enough to "keep" the Sub stable at periscope Depth if it was really well balanced by the L.I.

Quote from the novel "Das Boot" (losely translated): "You see, there´s a lot of physics and chemistry going to sea with a U-Boat!"

[THE_MASK]

What would you do different gameplay wise ?

[AS]

Originally Posted by sober

What would you do different gameplay wise ?

As I implied above: make blowing ballast tanks way more effective, making depths changes (especially going UP) faster, re-considering the amount of compressed air that is used in greater depths.

Later in war it was common practice to crash dive very deep (150-200m), and then they operated the submerged U-Boat for many hours. In "Wolfpack" that would hardly be possible or way too dangerous because of the (too) limited compressed air.


Cheers, AS