Boiler Explosions and internal damage
 

What signs would tell a prospecting Kaleun that he's hit a enemy ships boiler or other vital interal component?

One or more propeller stops. Or propeller RPM drops considerably.

If the boiler is punctured dose it create an explosion?

Are we talking real-life, or in-game effects of torpedo collisions? If the later, that depends on mods, mostly of the graphical kind.

If you see drop in speed after the torpedo impact, more than likely you have inflicted catastrophic damage

I meen like when attacking with the deckgun and shell hit's the ship where her boilers would be and the ship is ingulfed in a ball of fire(note this happens in both stock SH3 and GWX).

With the deck gun, (W' GWX) I noticed the ship can have Multiple huge explosions that look really great except that the ship keeps right on going. If you're playing GWX the ship will take many many shots from the deck gun to sink it. It saves torpedos but it uses up your deck gun ammo real quick.
D40 :salute:

Have a look at this. :03:

http://www.youtube.com/watch?v=zRCG7...eature=related
http://www.youtube.com/watch?v=JyCL6c0Sb_g

I use a trainer that gives me infinant deckgun and AA gun ammo.

My experience in GWX is that speed reduction and listing are the only reliable signs you have inflicted damage.

Yes, you can explode stuff off the deck, but that seems to be mostly eye-candy.

If I have a 10-knot tanker reduced to 3 knots and listing, I just stay submerged and bide my time. She'll go down.

with GWX ship sink by flooding, making things explode above the waterline may look cool but it is unlikely to cause flooding. aim at or below the waterline to get them to sink.
this massively different to stock, which works on hit points, hit a ship enough times (Wherever you like) and it will go down.