Torp Damage?

Not that this will matter when I start my career as I never use the event or outer camera mode, but I did in sub school.

Now the damage made by the torp(s) looks really really good, but the Q I have for anyone that has seen this happening ( free camera to watch the torps hit) is it only certain parts of the ship that will show damage?

I fired 2 torps at a ship and the each made hole in her, the hit were at least 30ft apart. i fired a and it hit right in the middle between these 2 holes, no damage from 3rd torp.

Could it be that the ship is already classed as sunk? then again i don't thnik that should be it.

I did a few tests, and as 1 torp hit and ripped a hole about midhips, my 2nd close behind hit only a few feet to the side of this hole, again no damage.

I might be wrong , but I thought I heard or read that the whole of the hull could be damaged.

or it that down to the graphic options the amount of damage caused.