In the Season 21 premiere, Sig and Johnathan head to abandoned Adak Island, chasing rumors of giant king crab. Co-captaining the Time Bandit, the two legends spark a gold rush out west, until chaos on the Titan Explorer forces Jake's crew to abandon ship.

After a deadly chemical leak forces Jake to abandon ship, Keith races to locate the Titan Explorer crew and save their ailing vessel; with Sig aboard the Time Bandit, Mandy takes the Northwestern's helm for her first-ever solo king crab season.

A typhoon brings monstrous waves and high winds to the west. Rick and Bob attempt to stitch a head wound in turbulent seas, while John risks capsize to make a harbor entrance. An emergency tests Jake between his duties as captain and man of the house.

A brutal knife injury on the Northwestern leaves Sig scrambling. After one crewman quits, tensions explode on the Confidence until even the co-captain revolts. The Wizard faces a nightmarish mechanical failure when Keith's throttle fails in rough seas.