Thanks for links ! Tons of information
Yes, I can compute drag from power and max speed, my results for LA is 0.23. This does not include the frontal area of fins or sail, so in the end it will be little smaller. And that is at max speed with some possible turbulence, so at lower speed it can be less. Anyway some real life data would be helpfull to know 'it fits'.
For now the most 'blank areas' in my math are: acceleration at zero speed and turn rate.
For acceleration at zero speed I now use simple estimate from max speed. The force needed to keep sub at the max speed is simple: power/speed. I use this force for all speeds. It gives acceleration of 0.017g. It takes about 25 seconds to reach 32 kts.
Horizontal movement is quite alright, I mean simmilar to DW. I'm tuning diving now. I'd like to add some simple particle syystem so sub movement is more obvious and then I'll make this public.