Torpedo settings?

[17thcpikeman]

Any advice on what settings to use and how to set them for torpedos?

I am on my first patrol (again) and have two types of torpedos, GI GII. I notice that the ranges of the GI is to about 12000 m and the GII is 3000m.
1 what torpedos should I use, which is the best?

2 at what ranges? I understand that at 12000m a ship has a greater chance of changing its heading so throwing the soloution off and therefore missing the target. I have been closing it about 1700-900m but the chance of detection is higher.

3. Magnetic or impact? I tend to use magnetic and have noticed that sometimes the torpedo just thuds against the side then sinks any advice?

4. depth of run, is this important? should i be aiming for as low in the water as possible? does this make any difference?

5. salvo over single. I tried for the first time last night a salvo of 2 torpedos and they both hit one in front of the bridge one behind the bridge and the ship sank quickly. in the past i have fired a torpedo then waited a second or two before launching the next one and having the torpedo hit in about the same area doe sthis do any extra damage or it the way the salvo hit better?

I have been against single ships upto now with success but convoys are proving more difficult, I panic and focus to much on one ship should I try and hit several to bring them to a stop then come back to them later instead of trying to sink them straight off?