Raw horsepower, lightning speed and roaring decibels will return to the Lewiston-Clarkston Valley this weekend when the Thunder on the Snake Jet Boat Race kicks off its seventh annual rendition.

Drivers, navigators and boats from as close as the valley and far away as New Zealand will take to the water in a series of races that test not only technical skill of drivers at speeds as high as 140 mph, but also the physical stamina of engines and equipment.

The race often is decided by the team that can keep its boat running, rather than the one with the fastest vessel.

Racers will be at the Clearwater River Casino in Lewiston, Idaho, from 4 to 9 p.m. Friday for a boat inspection and show and shine. The racing kicks off at 9 a.m. Saturday, with a long-distance run from Hells Gate State Park Marina at Lewiston to Bear Bar, a distance of about 32 miles. After a short break, competitors will race back downriver to the marina.

At 1:30 p.m., a second round of racing will have the boats jockeying for position as they sprint from a start line near the Lewiston Elks Lodge to Three Mile Island. The racers will go around the island and then head back downriver in a circuit that will be repeated three times.

Adding to the excitement, the circuit race will kick off with a mass start, with all the boats from each of the classes leaving at the same time instead of a tiered start that is featured in the run to Bear Bar. They will have about 3 miles to put space between themselves and other boats before circling the island.

The course can make for exciting spectating if boats are close to each other as they approach the island.

“I don’t think anybody’s gotten too dirty up there yet, but it’s bound to happen,” said Ryan Hudson of Lewiston. “It’s pretty rare to get boats neck and neck by the time they get up there.”

Hudson will pilot Top Gun, owned by his navigator, Tracy Popham of Lewiston. It’s a new sport and a new boat for Popham.

“I had never been in one until I built this one and it was just a great, fun experience,” said the former drag racer. “I went to Riggins and just fell in love with this sport.”

Hudson and Popham placed second at the Race The Joe at St. Maries this spring. Hudson said they are looking to top that on the Snake.

“We are going to take it. We are not going to get second again — that is the first loser,” he said.

Popham, who keeps tabs on the engine while also looking for river debris and other boats, said he has a high level of confidence in his driver and the boat that is painted like a fighter jet, complete with guns and sidewinder missiles.

“Those guys better not mess with us,” Hudson said.

The final race, another round trip to Bear Bar, will kick off at 9 a.m. Sunday. It will be followed by a 4 p.m. awards ceremony at the Red Lion Hotel in Lewiston.