In fact sounds like a more general point about torpedo gyro angles would help you out, going by what you said, though there are many here that would do a far better job at it than me!
The gyro angle is the amount your eel has to turn itself when you fire it in order for it to intercept the target. Zero degrees is ideal; that is you've calculated that the target ship will be directly in front of you at the time your toprpedo will find it so you simply fire your shot directly ahead (for your front tubes; for your rear tubes the ship will be passing directly BEHIND you at the point of impact). Anything more than about 5 degrees of gyro angle is problematic, which is why if you aren't aware that tube five points backwards you will never hit with it. Any poor torpedo you fire at a ship in front of you would have to make a massive turn in order to meet the target.
Also remember that at the point of impact your torpedo should hit the target ship as close to a 90 degree angle as possible or it will sheer off she hull instead of detonating. You can check this kind if thing early on as long as you have the event camera enabled. It's all about angles
