Make subs unable to traverse station turf/tiles

[Wisecrack34]

Ok, so is there any actual issues with the non-nuke subs? I feel like if you fire at a sub with any ranged projectile while in open oxygen it should apply the effects to the person inside to a lesser degree. I can see it being made so that in water it acts as normal, since water does slow down projectiles IRL. I feel this would fix the issues with people inside being too well protected whilst not causing issue to the people using them in the trench, thoughts?