— Minnesota fisheries workers on the North Shore will never denigrate the 25-foot Boston Whaler that provided them safe travel on Lake Superior for more than three decades.

But the heavily used fiberglass Whaler worked beyond its life expectancy. What’s now cutting waves, netting fish and dodging storms on the largest Great Lake is Blackfin — a sleek, all-aluminum vessel made in a Twin Ports shipyard expressly for the Department of Natural Resources.

Powered by a pair of offshore outboard motors and stationed at DNR’s French River Hatchery on a custom-made trailer, the finished rig was authorized for payment in May at the final price of $231,805. One of its first missions this spring was on rough water outside Knife River to assess the health and abundance of Lake Superior lake trout.

On that run, Cory Goldsworthy, the DNR’s North Shore area fisheries supervisor, operated a hydraulic net-puller while flanked by two fellow scientists who picked fish out of the seine. At three locations, they harvested more than 100 beefy lake trout from frigid water, 25 fathoms deep.

“There’s fish blood on [the puller],” Goldsworthy said. “It’s officially a work boat now.”

He said the 31-foot craft was custom-made to be safe, agile and comfortable. Marine engineers at Lake Assault Boats hit the mark, he said.

While Goldsworthy talked, Chris Palvere maneuvered the boat over a rolling 4-foot sea to get in line with another fish net. Water from high waves sprayed and then pounded against the boat’s windshield. It ran off the vessel as quickly as it arrived.

“It’s our little version of ‘Deadliest Catch,’ ” said Palvere, Blackfin’s primary captain.

Goldsworthy said Palvere communicated closely with Lake Assault, visiting the Superior, Wis., shipyard starting last summer with the first phase of construction. The long, thin boat was nearly completed by Christmas, and Palvere consulted with the makers right down to the final touches.

“He’s been dreaming about this boat for 10 years,” Goldsworthy said of Palvere.

With Palvere and Lake Assault still working out minor bugs in the newest addition to the state’s boat fleet, here is a rundown of Blackfin’s important features and functions:

Length and width

At 31 feet-long, 8 ½-feet-wide, it is made to handle Superior’s seas and accommodate deck work for three or more crew members. It has an enclosed, stand-up, center-steering console with a pair of mini-benches for passengers.

Weight

It was critical to keep the boat and trailer under 10,000 pounds. The finished sum is 9,610 pounds. That allows for an equipment payload of up to 2,000 pounds — often including heavy wet nets and hundreds of pounds of fish. Keeping the combined rig under 12,000 pounds enables DNR crew members to haul Blackfin over the road without obtaining a commercial driver’s license.

Power plant

Dual Yamaha V6, 250-horsepower offshore outboards ($25,650 per copy) delivered from Florida. Each engine draws from its own gas tank — a feature to safeguard against water fouling fuel. On calm water, Blackfin tracks at 51 miles per hour.

Wet deck

The Whaler relied on an electrical pump in its lowest inner area to expel water that accumulated from waves and rain. Not ideal for safety. Blackfin has no bilge. When water comes in over the gunwales, it runs off the vessel’s flat deck.

Trailer

Hand-operated and pulled by a heavy-duty pickup truck, the custom-built trailer ($14,125) allows Blackfin’s crew to get off Lake Superior and travel distances up and down the North Shore more safely than on the water.

Said Goldsworthy: “If something [weather] kicks up and you’re on the lake … that’s not good. You’d rather be trailering.” It loads and unloads as quickly as any 17-foot family boat.

Net lifter

A Crossley — ordered from the same small company in Maine that has been outfitting Great Lakes fishing boats for more than 110 years.

This $9,200 hydraulic puller mounted onto Blackfin’s bow makes seining in Superior’s extreme depths possible.

Buoy storage

A last-minute addition to the blueprint provides a long, narrow space atop the cabin for crews to quickly stow the weighted, 9-foot buoys that mark net sites.

Naming the vessel

Blackfin is the name of a large cisco and a species of whitefish believed to be extinct in Lake Superior and other Great Lakes. It was last seen in Superior decades ago and succumbed to over-fishing and predation by invasive sea lamprey. Its preferred habitat is deep, cold water. A signature decoration on this silvery fish was black coloring on the outer half of its fins. Similarly for the boat, Blackfin’s hull is black and its high sides and cabin are silver.