That reminds me one patrol when i first got SH3 (stock no mods).
I found a lone C3 and decided to engage with torpedoes because of the stormy weather. From a distance of about 700m and AOB 90 degrees i fired 2 torps aiming for the middle of the ship with the pistol set for impact of course.Both struck it and it got on fire so i waited for it to sink but nothing so i launched another torp and still no kill at the end it sunk after 5 hits. I got mad spending 5 torps for a C3 and reloaded my last save.