Newcomer Ken Kerr and the 600 ton beast Myrtle Irene threaten Shawn's plan to build his megadredge. The elements jeopardize Emily's plan to dive deeper. Kris heads to The Bluff with a new dredge, but faces complications

Dangers rise with the tide when Shawn has a life-threatening mishap underwater and Emily's dredge, The Eroica, faces a possible collision. George prospects for his brother Dave and his business partner Ken Kerr while the Kellys take home a chunk of gold.

Shawn and Kris battle encroaching miners; Ken's beastly Myrtle Irene continues to invade and operating costs soar; Emily expands her operation, but an air malfunction threatens her season.

In the Bluff's lawless waters, Shawn and Kris wield brute strength and make verbal threats while standing their ground against the competition; in Nome, Alaska, Emily and George gamble on new strategies and resources.

The approach of a violent storm pits safety against the drive to succeed; Ken rushes to free the Myrtle before it's destroyed; Kris risks being stranded; Shawn mines until the Bering Sea rips up his dredge; Emily attempts to appease nature.

A violent midsummer storm forces the fleet off the mining grounds. Shawn, Ken, Emily and Kris race to repair and improve their dredges for an end of season attack while reliving some of their most dangerous and triumphant moments on the Berinq Sea.

Shawn works overtime to cover for his exhausted crew. Kris is blindsided by the loss of his lead diver. Emily jumps in to prevent a fuel spill. Ken and George collaborate to find Myrtle a motherlode.

Winter winds force the captains to reevaluate risk and reward. Shawn's mega-barge extraction takes a turn for the worse. Ken pushes the Myrtle to the limit on a 5-day run. Emily sends her divers deeper. Kris invents a new form of prospecting.

In a race against winter, Shawn extends his sluice to get more gold. Ken pushes the Myrtle 24 hours a day. Emily tangles with the tide. Kris battles a bed of quartz and George enjoys a season-ending dive with his son.

Desperate to be Nome's gold king, Shawn risks the Christine Rose in dangerous waters. Ken struggles to free the Myrtle from the harbor. Emily fights a fouled airline and Kris attempts one more dive at the Bluff.

In a shocking confrontation, Nome's top two miners Shawn and Ken come face to face after a season of squaring off, having revolutionized mining with bigger, badder, gold-grabbing machines. Secrets are revealed through never before seen footage.