push too hard and it could put too much stress on "holly hock's" massive engines. not enough, and the ice stays put. break the ice wrong, it could make things worse. >> if we break too much, we will cause more ice jams and make parts thicker where we don't want it to be. >> reporter: they will do it all over again tomorrow. let's talk a little about the potential economic impact here. as you heard, a one-day trip, what's normally a one-day trip through the lakes is taking as much as a week. that means that things like iron ore that's going to the steel mills is delayed, stockpiles of that raw material for steel are low. that could potentially lead to production delays if this persists. up in the northern tip of lower michigan, that is a key point for trafficking of all of this iron ore, things like that, through the great lakes and those are normally closed this time of year. they will reopen in about a month and they want to have a smooth start, but that's a concern because of course, it's obviously even colder up there and the last time the ice was this bad, they

coast guard cutter "holly hock" on one of the nation's most vital shipping routes.the controls yet? i see not. >> reporter: no, and i think that's probably a good thing for the good people of michigan and canada, just to make sure i sort of show you around a little bit. there's a crew of about 50 people normally aboard this ship. a lot of very skilled people throughout the vessel. here on the bridge, you can see it takes quite a few people to drive this, they are monitoring navigation, monitoring the ice both through radar and also their own experience in dealing with different patterns of the ice over the years. the man in charge of it all is lieutenant commander justin kimora, the' captain of this vessel. you were telling me this is the worst ice you have ever seen in the three years you've been up here and a lot of people, even longer. what kind of pace are you working at? >> we have been working pretty hard, a lot faster tempo than we normally do. this is my third winter up here. this is by far the worst scene i have seen in the st. clare river. we have been wor

that's the product of the work here on the coast guard cutter "holly hock."that that refreezes and when it refreezes, it's thicker than it was before. basically about two feet thick and so they have to keep on going back and forth and essentially plowing out this path. let's give you a sense of what our mission is today. so, we started out about 8:00 this morning from port huron in michigan, about the southern tip of lake huron, we're heading down the st. clair river to lake st. clair and basically continuing to clear out this path ultimately this pathway leads into lake erie. lake st. clair, the detroit river and then lake erie, a very key passageway. and as far as ice goes in wintertime, it really doesn't get a whole lot worse than this. >> this is my third winter up there. there is by far the worst i've seen talking to some of the locals, this is the worst winter they've seen in their lifetime. beyond that, i don't know the numbers, but from our perspective as well, our mission, it has, you know -- it has placed a, you know, we're working longer hours, usi