Question about torpedoes
 

I can tell that a torpedo set to impact detonators is better than one with magnetic, although there is a chance to bounce off if there's a certain angle.
What i CANT tell and im asking your opinion in this, is this:
Lets say we have a shot amidships on a battleship. Is it better to have a near surface torpedo, set to impact detonator or to have one a bit below the ship, set on magnetic detonators so we can have something like this:http://www.youtube.com/watch?v=vYAWrkvyYdc

I know that impact detonators can cut in two a ship as large as a medium cargo but wouldnt an explosion underneath the ship cause enough damage to flood at least a couple compartments?

Any explosion in close proximity to, or at, the hull can cause a breach which will lead to flooding. However, for larger ships, only a magnetic exploding under the keel has the potential to break the keel, thereby ripping the ship in half.

Personally I just look at what angle I'm approaching the target at Head on, Magnetic under the hull From the side, impact into the guts