As ominous red skies forecast a storm on Lake Michigan, Captain John "The Legend" Selvick races out of port to try to beat the weather--only to be sidetracked when his rookie first mate, Chris Costello, almost sinks a smaller tug in a dangerous maneuver. Across the lake, John's trusted right hand, Captain Ted Long, is forced to make a decision: stay in port losing money, or risk it all--and face the very real possibility of losing his haul or sinking his tug in the oncoming gale. On the northern reaches of Lake Superior, Captain Stan Dawson attempts a rescue mission in the middle of a blinding snowstorm.

When "The Legend" Captain John Selvick brings on a replacement to teach his rookie first mate, Chris Costello, a lesson, his plan backfires. Across Lake Michigan, Captain Ted Long stares down one of the most challenging hauls of his career: six oil containers standing upright at 80 feet tall, prone to being toppled by even a small gust of wind...bringing Ted and his men down along with it. Up on Lake Superior in Duluth, the upstart tug captain Mike Ojard tries to make a name for himself by taking on an ice-breaking job that would challenge a veteran skipper - and nearly gets crushed in the process.

Two storm fronts are on a collision course for Lake Michigan, and Captain John "The Legend" Selvick is caught in the crosshairs with over a million pounds of cargo that almost goes overboard. Captain Ted Long steams North on a 100-mile run through a graveyard of wrecked ships, before traversing one of the most dangerous harbors of his career. In Duluth on Lake Superior, a career-making job comes in, and upstart Captain Mike Ojard and his family risk life and livelihood that a 44-year-old used tug can become a monster ice-breaker.

Fatigue threatens the crew when Captain John "The Legend" Selvick pushes them when he attempts to do something he s never done in his x-years on the lakes. Meanwhile, Captain Ted Long unleashes his alter-ego "Captain Nice" loses it on his un-communicative crew in the face of a 30-million-dollar barge move through Indiana Harbor s notorious "Chute". On Lake Superior in Thunder Bay, things heat up when Captain Stan is forced to work with his novice nephew, and ice-breaking for a massive fuel freighter goes from trail by ice--to trail by fire.

Captain and owner of Calumet Fleeting, John "The Legend" Selvick, struggles with his nephew Ricky's inattention, and doubts whether one of his own has what it takes to carry on in the family business. Meanwhile, John's stepson, Nathan Schley, is asked to take on a big job for the company--but just getting there will take this young captain through the infamous waters of Death's Door. And Captain Ted Long struggles with a crippled engine while threading the needle of the notorious "Iron Curtain.

In the wake of a severe winter storm, Captain Nathan Schley--stepson of John "The Legend" Selvick, leads a job for the first time without The Legend at his side. When boats get frozen into the dangerous harbor ice, the job seems destined for disaster. Meanwhile, in Thunder Bay, smoke in the engine room forces Captain Stan to abandon a lucrative job--while his Nephew Nate Dawson wrecks a tug at dock. On the South End, Captain Ted Long is forced to work twice as long--and twice as hard, on a junked out tug, bound for the scrap yard.