I know it's a bit of a nitpick but considering we're watching our wonderful type 7 in a side view so much in this game I can't help but to wish for slightly better physics. The sub bounces around more like a cork, there is no indication that the propellers are actually giving the forward momentum which on the surface will push the bow upwards and push the stern downwards by an amount depending on force (how hard you're running the engines).

This will naturally be different when submerged, since there's more equal pressure both up and down.