Funny, I was just wondering about this while having a shower. Could rail gun ordinance be used under-water, say, to take out a sub? It seems like you'd face th

Funny, I was just wondering about this while having a shower. Could rail gun ordinance be used under-water, say, to take out a sub? It seems like you'd face the same problems as you would with in-air ordinance, just to a greater degree (e.g. friction). The objective might be slightly simpler though: rather than delivering maximum kinetic energy to the target you instead just want to punch a hole through it. That change in objective might simplify the design of the 'underwater rail gun' ordinance: just use some nice heavy ferromagnetic metal, shape it to reduce drag and pierce armour (i.e. make it pointy) and maybe coat it in teflon? I dunno, not really a physics or weapons nerd here. I just like magnets :) EDIT: just to clarify, I'm thinking of torpedo defence in the context of 'destroy the sub before it gets within range'.