Notes on the Type XXI

[Marcello]

I will use this thread to post informations and personal observations on this type of u-boat. I use GWX,Commander, Stiebler patch and Wreford Type XXI mod (plus SH5 water mod and ASDIC MKI)

Speed settings I use
- Transit: 5 knots + surface runs at full speed in foggy/bad weather or when enemy air is relatively light.
- Transit in case of heavy enemy air presence: 4 knots
- Snorting and using the periscope: 3-4 knots
- When looking for targets in the patrol area: 1-2 knots
For reaching and leaving the patrol area I have come to the conclusion that in the game a speed of 5 knots is the best compromise between the various factors.Assuming 100% charged batteries at the start and a 15 minutes snorkel run to replenish air supply it will leave you with about a 70% charge at the end of the daily run; enough to deal with any emergency. Thereafter batteries can be topped again in three hours and half.
Only when I do not plan to engage anything along the way and enemy air is less pressing I will push to 6 knots.
On the surface I will usually run at full speed to minimize diving time, though in the safer areas I may run at standard speed.

In real life ther snorkel was often used at 5 knots, personally I find that the vibrations in the game at such speed are not worth it, however useless the periscope might be to detect aircrafts I still prefer to be able to look around. On the other hand going too slow is not practical as there will be depth keeping issues and you want to minimize snorkel/periscope exposure.