yeah cargos are a b*** to sink
I found out that hitting them on various spots works better. I go for 1st bellow the smoke stack 2nd one 10m before the bow and if needed the 3rd nail in the coffin goes in the middle of the ship (betwen 1st and 2nd shot)
But still- I once used 5 eals and the C2 was still afloat and GOING 10 knts- took another 10AP and 15 HE to take her down in the kingdom of davy jones
tankers on the other hand are easy in my experiance- 1 or 2 in the middle and they break in half or stay afloat but burning like a torch and later finish their life in a massive fireball
