I hate to say it but this tactic of your is highly irregular at best and suicidal at worst. Your ideal firing position is for you to be exactly perpendicular to the ships project track closing at small speed. You are thus presenting a small target to the enemy while having the advantage of her entire broadside. What is called in maritime warfare crossing the "T". Hard for them to hit you is easy for you to hit them.
Lest we forget we are driving subs NOT battleships!
Regards,
Immelman