can you "duel" other submarines in game?

[Schwieger]

You guys know that I-29, I-168 and I-351 were sunk by American subs right? And that SS-226 was sunk by a Japanese submarine?

That should help flush out your list

[razark]

Originally Posted by Schwieger

You guys know that I-29, I-168 and I-351 were sunk by American subs right? And that SS-226 was sunk by a Japanese submarine?

That should help flush out your list

Which of those involved two submerged submarines?

[sergei]

Originally Posted by Schwieger

You guys know that I-29, I-168 and I-351 were sunk by American subs right? And that SS-226 was sunk by a Japanese submarine?

That should help flush out your list

As has already been stated, there were dozens of subs sunk by other subs in WW2.
But in all but one case (U-864) the sub that was attacked was running on the surface.
U-864 was the only submerged sub torpedoed by another sub.
And even then, the only way HMS Venturer could track her well enough for a firing solution was because she was snorkelling.

The technology of the time was just not good enough for fully submerged sub v's sub combat.