No credit for sunk ships

[Shadowblade]

it happens to me a lot that I will sink respawned ship and waste the torpedo and deck gun ammo on it. Last time it happened to me on current patrol that I sunk two Large merchants and some hours after that I saw a convoy and another Large merchant. Lucky me, I said and sunk the merchant first...and was pissed of that it was just duplicate ship and got no credit for my work.

I wish that there would be some mod or fix to mark the duplicate ships so I will not waste my torpedoes and ammo on them...