As Sig Hansen approaches "greatest of all time" status as a Bering Sea crab captain of nearly a half century, his hard-won ways are put to the test when daughter Mandy Hansen pressures him to cement her spot as heir to the Hansen Family Legacy.

In the season finale, Keith risks pushing through jagged ice in search of the Wizard's lost pots. Attempting a risky harbor entry, Wild Bill overturns the Summer Bay and a beloved crewman makes the ultimate sacrifice on the deck of a veteran crab boat.

When processors shut down due to outbreaks, Sig bets he can zero in on a rare "crab highway" before there's no place to deliver. Josh and Casey race to deliver live crab after their pump fails, while Harley risks shipwreck to be first to enter St. Paul.

Jake battles a hurricane in the fleet's smallest boat while Keith orders crew over the rail to avoid capsizing. When Johnathan discovers crab in his cod pots, his crew scrambles to locate the hoard as "Blind Dog" finds himself in a bone-crushing position.

Cornelia Marie skippers Josh and Casey follow a blind tip from an unknown fisherman into uncharted waters. Johnathan fears for the worst when Freddy lands in the icy Bering Sea. On the Wizard, Captain Keith tempts fate, risking thousands in crab gear right at the ice edge.

An Arctic storm blasts the fleet as Sig ventures to deep waters he hasn't fished in 17 years. Johnathan steers the Time Bandit into 30-foot waves in a hail Mary run toward Russia. Captain Keith attempts a risky maneuver to save the Wizard's pots.

Captains scramble to meet an expanded quota in the path of a violent system dubbed "Squall-pocalypse". A breakdown on the Wizard puts Monte in debt to the Time Bandit and Josh and Casey exceed their own quota when it comes to injuries on deck.

As canneries unexpectedly change delivery rules, captains must race to get to the front of the line. Jake risks a daring entry into St. Paul harbor, as Johnathan seeks help from Wild Bill. Josh and Casey bet their season on a deep set at the Russian Line.

Skirting the ice line to the deepest set of their careers, Josh and Casey apply frontier medicine to a bleeding deck boss. A block wound sidelines Wild Bill's new rail man, while injuries on the Time Bandit take out two crewmen and threaten family bonds.

As the fast-moving ice edge crushes all in its path, Sig and Mandy rush north to rejoin the fray. On the Cornelia Marie, Josh and Casey's race to save their pots comes at a cost in blood and pain. Heavy freezing spray threatens to capsize the Wizard.

Sig makes a desperate bid to save his gear from the descending ice pack while Jake dumps pots to avoid capsize. When Wild Bill gets a line caught in his propeller far from Dutch Harbor, he enlists Jake's diver to attempt a risky underwater repair.

As a polar vortex storm slams the Cornelia Marie in the far north, Josh navigates the biggest seas of his career while Casey performs emergency surgery. A catastrophic collapse of the Northwestern's crane leaves Sig and Mandy with no way to haul pots.

As seawater floods in, Wild Bill's crew rushes to find a hole in the Summer Bay's hull. Johnathan faces a fire on the Time Bandit and the Saga has a hydraulic failure.

When Johnathan trusts his instincts more than his partners, the Time Bandit makes a surprise appearance in the Northern Grounds just as Josh and Casey need him most. Sig puts his crew exactly where they need to be in a matter of life and death

In the Winter premiere, the fleet reels from the loss of Summer Bay deck boss Nick McGlashan. Wizard and Cornelia launch early into a massive Arctic storm. Johnathan can't see eye-to-eye with an old friend and shocking news forces Sig to change his plans.

Time Bandit and Cornelia Marie race for the last spot at the cannery, but as word spreads of an emergency shutdown of the Bairdi fishery, they return to the grounds as Sig Hansen rallies his fellow captains with an unconventional plan.

With the Bairdi fishery open for the first time in years, Josh and John on the Time Bandit reopen the Phil Harris playbook and ask Casey and Sig to help tank the fleetwide quota. Wild Bill bets on Nick McGlashan to turn the tide for the Summer Bay.

Johnathan and Sig partner to hunt the elusive Bairdi hoard at the edge of the Restricted Zone. Jake earns an unexpected windfall of King Crab quota, but extended fishing and mechanical failures put safety at risk just as the Coast Guard boards the Saga.

As a typhoon rocks the Bering Sea, the Summer Bay suffers a collision. Sig gambles all his pots in one spot, while Casey takes a scientific approach to finding the elusive Bairdi crab. John and Josh rush a pit stop to get the Time Bandit back in the hunt.

Driving the Time Bandit and Cornelia Marie, Josh and Casey attempt Johnathan's strategy for tracking King Crab across time and space. On the Summer Bay, Wild Bill's crew fights a mid-gale power outage, but the days are numbered for their greenhorn.

Jake attempts a daring nighttime rescue in high seas as hundreds of dolphins lead the Summer Bay into a cyclone. Later, Sig is forced to make a controversial call to save the fishery.

When Mandy devises a plan for partnering, Sig must rethink his own tactics. On the Time Bandit, John and Josh conspire to outmanoeuvre a Russian captain.

With half the crab boats tied up, Sig devises a plan to save the fishery from destruction. As Bering Sea legend Johnathan Hillstrand returns with the Time Bandit to help, veterans struggle to prove they can work together to defend the American dream.

A depleted US crab fleet arrives in Dutch Harbor to an industry in crisis. Captains and crews discuss past season and the trials ahead.