“Bering Sea Gold: Under the Ice” 9 p.m. Friday, Discovery

It may only seem as though every time Thom Beers creates a new reality series, he strikes gold. As for the three half-frozen crews on his latest creation for the Discovery Channel, pay dirt is more elusive — a lot more elusive.

“Brutal,” Shawn Pomrenke intones, Ishmael-like, at the top of “Bering Sea Gold: Under the Ice.” “Brutal is the life of a miner. Gold don’t care about the ice. If gold don’t care, neither do I.”

As the show’s title indicates, “Under the Ice” is a spin-off of Beers’ other show about mining for gold in the waters off Alaska. The original “BSG,” launched last year, focuses on the summer gold rush in the Bering Sea as mining crews take advantage of the warmer weather to dredge as much gold as they can find from the floor of the sea before winter sets in and the Bering freezes over.

That is challenging enough, but when it comes to undersea mining off Nome in the dead of winter, the tough get going, but the tougher take on the even more treacherous challenge to go for the gold beneath a 4-foot-thick layer of ice.

With Beers narrating, we meet three crews who may share the same shiny goal, but bring different skills, equipment and temperament to the search.

The Shamrock is run by Shawn Pomrenke, whom we know from the original “BSG” as the son of Steve Pomrenke, owner of the Christine Rose mining vessel. The Shamrock crew has the best equipment money can buy, but that’s no guarantee against the deadly business of diving through a grave-sized hole in the ice into 28-degree water.

The Lazy Gator gang is at the opposite end of the readiness spectrum. These guys have all worked in other mining crews, but have scraped up virtually every penny of their own money to form a new crew. They don’t even have a chain saw to chop through the ice and have to use other methods. What these guys don’t have in fancy equipment, they make up for in grit and drive.

We’ve also met the third crew before. Zeke Tenhoff of the Clark was working and living with Emily Riedel in the original series, while her dad, Steve, was part of the Wild Ranger crew. But the intensity of mining, on top of always being together, put a strain on Zeke and Emily’s relationship, and Emily bolted, feeling burned out. Now she’s back, but so is her dad, working with the Clark team this time. Zeke thinks it’ll be good to have Steve around because Emily can fight with her father instead of bickering with him.

Unlike a lot of reality shows, “Under the Ice” is convincingly frightening. Even the smallest equipment failure can mean the difference between life and death, and as a viewer, you feel it. Imagine descending through a small opening in the ice into below-freezing water with limited visibility. Granted, there are obviously other people down there with the diver filming the whole thing, but it’s a testament to how well “Under Sea Ice” is produced, filmed and edited that viewers won’t think about that. Instead, they’ll be focused on what it would be like to be swimming around in what could easily become your watery tomb.