weeks than it used to be. i have seen erosion and the submarine, which was an amazing experience. you see what's happening as that ice moves apart and the likelihood of shipping and more activities happening in the arctic and i'm just so appreciative of our navy really experimenting up there and really increase iing our readin. >> they are trying to figure out how to navigate this, literally, and figuratively, how to project what our navy surface ships are going to be doing, given the changing topography. >> that's right. the interesting thing, as you were on a submarine that, while the depth is deep, you have sta lag hits hanging on below. the deepest one i saw was 60 feet below the surface that are protruding down. it's quite dangerous for submarines and ships and our navy is helping us understand how to navigate those extreme