When the government closes the King Crab fishery, captains must save an industry they worked so hard to create. Sig pursues invasive Russian King Crab in Norway; John, Josh and Casey chase rising prices for a new species, and Jake mortgages the Saga.

An Arctic storm slams the fleet already reeling from the closure of King Crab. Seeking a new species, Johnathan sets pots deeper than ever before. Sig struggles to launch his Norwegian operation, while a deckhand fights for life on the Patricia Lee.

His deckhand crushed by pots, Captain Rip charges into the Arctic storm to attempt the riskiest USCG helicopter rescue in recent history. John fights to save the Time Bandit at anchor, while Sig takes his first Norwegian rogue wave, flooding the Staalbas.

Sig struggles with a Norwegian crewman who thinks he knows more than the captain. Captain Wild Bill fights to save his boat from the rocky Norwegian coastline with a line snarled in his propeller. Keith's greenhorn faces a violent brush with death.

When Shyanne discovers a serious breach on the Saga, Jake and his crew scramble to save it from capsizing. In Norway, Sig drops pots on Russia's western line. As canneries close their doors, Josh and Casey call in a last-minute favor from Johnathan.

Sig scrambles to get home for Bairdi and Mandy's baby as his crew finds a honey hole of Russian King Crab. Josh's brother Shane gets caught in the bight as a typhoon slams the Cornelia Marie. Rip faces a crisis when a greenhorn collapses unconscious.

Johnathan searches for a pot of Golden Kings at the end of a double rainbow. A medical mystery confounds Captain Rip when his greenhorn regains consciousness on the Patricia Lee. Keith partners with Josh and Casey until John steps in.

Johnathan sets mile-deep pots and pulls up an unknown species. Jake faces reality when his niece, Shyanne, gets injured on the Saga. With Mandy's due date approaching, Clark takes the helm in Sig's wheelhouse to help tank the Hansen family Bairdi quota.

Mandy's pregnancy complication forces Sig and Clark to reconsider their stand. Jake and Rip team up in deep waters to battle powerful Aleutian tidal currents.

Johnathan risks losing his entire live catch when the Time Bandit ventures into fresh water. Josh experiments with glow sticks to attract crab at the darkest depths.

With dock prices spiking, the fleet races to deliver. Jake witnesses a freighter severing his longline, forcing the Saga crew to drag the bottom for a valuable string of pots. Rip helps Johnathan locate the motherlode only to pay with a broken block.

In an epic Fall season finale, Clark scuttles Sig's partnership with Harley to get home for the birth of his and Mandy's baby. An orca leads the Cornelia Marie to the season's best pots. When John's autopilot fails, Jake is the star that leads him home.

In the Winter premiere, nautical weather slams the fleet as Josh and Casey race north in hopes of beating the coming ice pack. Sig and Keith attempt to find common ground, and on the Time Bandit, Johnathan finds his co-captain a bit wobbly. 300th episode.

The Northwestern loses steering when a bald eagle lays claim to its mast. Sig and Keith develop an unusual partnership to tank Bairdi in record time. Josh and Casey place a risky bet on hard-to-find quota, while casualties mount on the Patty Lee.

New-mother Mandy returns to Sig's wheelhouse but as heavy ice builds on the Northwestern, she reckons with the risks the family is taking. Jake unveils a new super pot to stake his claim in the unforgiving cod derby as winter weather blindsides the fleet.

A dangerous list forces Sig to jettison pots or capsize the Northwestern. One wrong move in the narrow False Pass causes Jake and the Saga to hit bottom. There's no accounting for taste when Sean Dwyer devises motivational punishments for greenhorns.

Keith recruits Johnathan to intercept a Russian trawler fishing illegally in US waters but the situation intensifies when the Time Bandit crew spots a missile streaking across their position. Bill and Sean fight to defend their pots from rogue trawlers.

Josh and Casey race to the approaching ice edge as an Aleutian storm slams the opilio grounds. Jake discovers his niece and engineer have been hooking up more than crab gear as they risk life and limb climbing the 30ft crane to make a critical repair.

The Cornelia Marie crashes into the ice pack when the greenhorn on watch falls asleep at the wheel. Jake's crew experiences a stunning phenomenon when a flock of seabirds bombards the Saga. Wild Bill tackles an unsafe sea state on the Summer Bay.

After risking his crew salvaging gear from the ice pack, Sig changes tactics deploying an experimental bait from Norway. On the Time Bandit, frustration boils over as Freddy tests Johnathan. Jake hauls in seas so volatile his crew must take shelter.

With intense currents holding back the Arctic ice pack, Keith drives into deck-wrecking waves to retrieve his catch before the ice bounces back. Jake and Sean face losing everything when ice swallows their gear as Rip enters a pot cemetery of his own.

The icy depths of the Bering Sea threaten to claim Sig and Wild Bill's gear unless they can move quickly enough to beat the rapidly freezing waters. Rip takes on a massive amount of extra quota and if he can't catch it, he'll have to buy it.

As ice blocks St. Paul Harbor, captains race to deliver their final snow crab. Sig deploys a risky tactic his father pioneered, while Jake battles a slack tank to save the Saga. Keith and John scuttle a plan as the Wizard's 77-year-old hull cracks open.