What are some good sub tactics in SH5?

[JimmyS1985]

I just got done watching Das Boot and I saw somethings that I never thought of to do in the game, in the movie. I installed IRAI so I expect the destroyers to be more aggressive and harder to avoid than the incredibly dumb ones with the regular game. THe first time I heard a sonar ping from another ship was after I installed IRAI, even with 60 hours of gameplay.

For example, is it a good idea to turn while you submerge, to avoid depth charges? I always went down and kept on my course. I haven't had enough depth charges dropped on me to find out if thats a very n00b tactic. How do I get full rudder, instead of getting the rudder to turn only 5 degrees at a time?

What is the radio used for, asides spotting convoys so far away you will never intercept them? I still haven't gotten to a campaign that requires milk cows.

How do you locate a ships exact location using the hydrophone in SH5? What kind of math skills does that require? Can I sink a ship using only the hydrophone, or should I get visual contact first, regardless?

WHy do they dive so deep in the movie? What is the crush depth for our subs in SH5 and what are the advantages of diving super deep? I usually dive to 40m or so and thats plenty, but in the movie they go all the way down to 280 meters, is that depth even possible in the game?

And just what are some basic need to knows, like how much hull integrity should you have left before considering running back to base? What are the advantages of a simple refit versus ending a patrol? What is a lethal amount of Co2 in the game? How come the game only lowers time compression when Im already being sunk by a destroyer?

I really don't know what Im doing in this game as the tutorial was entirely lack luster. One final question, why can't I dive to a specific set depth? Its always either crash dive, dive, periscope or surfaced.