MANCHESTER — As Martin Goulet and his 7- and 9-year-old step-daughters struggled to hang onto a steel boat barrier cable spanning the Merrimack River last August, the powerful Amoskeag Falls churned just 300 feet away.

Had they lost their grip, the three would have had just seconds to live after plunging over the 55-foot falls, Manchester Fire Lt. Paul Smith said.

Smith and firefighter Joshua Guay are being honored with a Union Leader Hero Award for rescuing the trio.

The afternoon of Aug. 29, 2011, was sunny and beautiful. Goulet, of Concord, decided to take the girls out for a ride on a personal watercraft. It was only days after Tropical Storm Irene hit New Hampshire,

As the three neared the boat barrier — a steel cable stretching across the river with buoys attached — the watercraft swamped and the engine died, according to Guay. The three grabbed the cable and hung on.

A PSNH employee working at a utility building near the falls saw the watercraft bobbing in the falls and called over to a co-worker, “Hey, there's people hanging on the buoys.” They called 911, Smith said.

When the call came in, the department's four-member Rescue 1 team was 10 miles away, testing the swift-moving current of the Merrimack River near the Manchester-Boston Regional Airport. The current turned out to be moving at 18,000 cubic feet per second — the fastest Guay had seen it since the Mother's Day flood of 2006.

The team raced across the city; more than 20 other firefighters headed there as well, including two boats from Manchester's Central station and two others from the Bedford Fire Department.

By the time Guay, Smith and the other two members of the team arrived, 15 minutes after the call came in, the boats were ready to launch.

Smith — a charter member of the specially trained Rescue 1 unit formed in 1988 — said he steered the boat upstream and then swung back, heading for the boat barrier. Guay guided him to the spot. It was only as they got closer that Guay realized there were two little girls grasping the cable.

“I was just glad I had sunglasses on because I didn't want the kids to see how scared I was,” Guay said.

The two girls were about the age of his own two daughters, he said.

“I just thought of my kids and they (the girls) were doing amazing holding on to that cable,” said Guay, who has been with the department 11 years.

He remembered telling Smith afterward he had decided if one of the girls let go of the cable, he was going into the river after her.

“He said if that would have happened, both of you would have drowned,” Guay recalled.

The girls were on either side of their dad; all three were wearing personal flotation devices.

“I remember him saying to me, “Grab them first. Grab them first,” Guay said of Martin Goulet.

And he did, first yanking one girl up and over into the boat and then grabbing the second child and pulling her to safety. His attention then turned to Goulet, who was exhausted.

“Kick, kick,” the firefighter told Goulet, who said he couldn't. Twice, Guay tried to pull the 180-pound Goulet into the boat. Twice, he failed. Smith couldn't help because he had to control the boat. Finally, Guay planted his legs against either side of the boat and hoisted Goulet in.

Now, it was up to Smith to get them to shore, no small feat given the current. First, he tried to reverse the engine, which sent a wave of water over the boat. He eventually maneuvered the boat to the opposite side of the river, landing at a private condominium launch site.

In a statement thanking the rescue squad, and particularly Guay and Smith for risking their lives to save the family, Goulet said he and his stepdaughters suffered only minor scrapes and bruises.

Both Smith and Guay downplay their roles in the rescue, insisting it was a team effort. And while many were critical of Goulet for taking the girls out on the river, both firefighters praised the stepfather for maintaining his composure and helping his stepdaughters to hang on.

Smith said the three are here today because everything seemed to line up.

“It only worked out because all the right pieces were in the right place at the right time,” he said. “It just wasn't their time to go.”