A frightening accident aboard the Time Bandit turned into a desperate race for medical help on Deadliest Catch — with Capt. Johnathan Hillstrand forced to steer through monster 17-foot seas to get an injured crewman back to shore.

The drama unfolded during the Friday, Aug. 14 episode of the Discovery series when greenhorn Ryan suddenly fell from his bunk and slammed his head.

Footage from the boat showed blood around the bunk and running from a nasty gash across Ryan’s forehead.

“He just fell out of his rack and smacked his head,” a producer explained before alerting Hillstrand to the accident.

The 64-year-old captain immediately rushed in to help, telling Ryan to lie down, stay calm and avoid moving while the crew worked to patch up his forehead.

But Hillstrand knew a head injury at sea could quickly become something far more serious.

He told the crew to watch Ryan closely and warned that if the injured man started vomiting, “we got problems.”

Before long, Ryan appeared confused and disoriented.

When someone asked how his head felt, Ryan replied, “Not good.”

Even more alarming, he reportedly couldn’t remember Hillstrand treating his injury just moments earlier — raising fears that he may have suffered a concussion.

“He’s in pretty bad shape,” Hillstrand said. “We can’t take a chance.”

That left the veteran captain with a brutal decision: turn the Time Bandit around and head back toward St. George Island in dangerous conditions.

The boat had already battled rough weather near the island earlier in the trip, with Hillstrand navigating through roughly 15-foot swells near the narrow entrance to St. George Harbor.

Now the seas were even worse.

“I’m trying to make it to the island, take our patient to the clinic,” Hillstrand said. “I gotta get into the harbor. It’s not an easy thing to do here.”

The Time Bandit was facing a 17-foot following sea, with huge waves threatening to shove the 113-foot fishing vessel off course and toward the rocky shoreline.

Hillstrand’s brother, Neal, urged him to take the approach “slow and steady.”

But there was little room for hesitation.

“There’s gonna be a point in time where we can’t turn back,” Hillstrand said. “I just gotta go do it.”

As the Time Bandit approached the harbor, the vessel began riding the massive swells toward the entrance.

At one terrifying moment, the boat was shoved sideways, sparking concern inside the wheelhouse as Hillstrand fought to straighten it out.

The captain managed to regain control and safely guide the vessel into the harbor.

Only after making it through did Hillstrand reveal just how nerve-racking the trip had been.

“Why am I sweating bullets right now?” he joked after the dangerous maneuver.

“We got a little bit of a sleigh ride coming in there,” he added.

Ryan was eventually taken to a clinic, where he was expected to need stitches. He also had to be examined and cleared by a doctor before being allowed to return to sea.

The episode, appropriately titled “Those in Peril on the Sea,” featured plenty of other chaos across the Deadliest Catch fleet.

On the Northwestern, Capt. Sig Hansen and Sophia “Bob” Nielsen were forced to change their fishing strategy after back-to-back injuries left the deck crew short-handed.

Meanwhile, Jake Anderson faced a potentially disastrous emergency when the Cornelia Marie suddenly lost power while battling heavy seas.

The outage left the vessel without normal power and hydraulics as the crew scrambled to fix the problem.

With the boat rocking in dangerous conditions, Anderson warned there was “no room for error.”

Deadliest Catch airs Fridays at 8 p.m. ET/PT on Discovery Channel.