PRESQUE ISLE, Maine — For Randy Lord, life as an amputee meant a lot of changes after he lost a leg below the knee in a work-related accident.

He needed to learn a new way to walk with a prosthetic, a new way to climb stairs and a new way to drive.

He eventually adapted and began seeing more and more amputees such as himself getting around and staying active.

But there was one place he did not see amputees too often, and that was swimming in the ocean.

Lord set out to change that by creating special fins he and others like him could use.

Lord said Sunday during a public trial run at the University of Maine at Presque Isle pool that the Amp Fins will give amputees a sense of normalcy and put the fun back in summer vacations and workouts.

“When you’re at the beach, you go to walk and sit down, and you get sand all through your prosthetic and that is bad,” he said. “You go into the water, and if you put a normal prosthetic in seawater, you’re putting between $8,000 and $15,000 worth of money in a saltwater environment. It deteriorates it.”

When Randy and his wife, Lori, of Danforth first began looking at options, they used existing prosthetics and tried to fit the fin to them. But they found these were cumbersome and often left Lord unable to comfortably wear his prosthetic after a swim.

“We had to overcome a lot of obstacles in our design, one of the biggest being that there could be no chafing happening while wearing the fin,” Randy Lord said. “Chafing leads to real discomfort when you put your prosthetic limb back on, and we certainly did not want to hinder the ability to get around after a swim by using our fin.”

Swimmers can wear the Amp Fins all day long without suffering any side effects, according to the two inventors.

The swim fin fits directly onto the amputated limb. G+G Products LLC of Kennebunk has been instrumental in the creation of the prototype molds.

The Lords brought their invention to Cory LaPlante, an above-knee amputee and certified prosthetist at Northern Prosthetics & Orthotics in Presque Isle. LaPlante reported that within 30 seconds of wearing the AMP Fins in the pool, he had totally forgotten he was an amputee. Not only that, he said, he felt muscles working he hadn’t felt in years, opening the door for the fin’s use as a means of physical therapy.

The Lord’s said they have a patent pending on their design in the U.S. and other countries.

Amputees using these fins will have an advantage over able-bodied swimmers using fins, the Lords said. The couple explained that in swimming with fins, the ankle is the “weak point” of the kick.

According to Randy Lord, on the backstroke of the kick an able-bodied swimmer loses 80 percent of his or her power because the ankle cannot handle the strain of remaining straight. With the Amp fin attached directly to amputated limb or limbs, amputees are able to produce 100 percent power in both directions of the kick, propelling them with greater speed and efficiency than able-bodied swimmers, he said.

“Finally, amputees will be able to say that they can do something better than people with legs,” Lord said Sunday. “Able-bodied swimmers will have to try and keep up.”

Five amputees already have been helping the Lords test hard and soft versions of the Amp Fins.

Each participant has been fitted with a glove-like shell of his or her amputated limb, which was glued into the fin and covered with a neoprene sleeve.

On Sunday at the UMPI pool, Donna O’ Brien, a double amputee who lost her limbs in the late 1970s, when she was in high school, swam for about two hours.

“I love them,” she said. “I did not like the hard ones as much as the soft ones, but I think the soft ones are great.”

O’Brien said she also has used the fins in therapy with LaPlante. When she had a minor problem with the fins early on, it was fixed quickly and she was back to swimming in no time, she said.

“I have one leg where the muscles in it I have not really used in swimming as much as the other, and I can feel it,” she said. “These are great.”

The Lords said representatives of the Shriners Hospitals have contacted them about making Amp Fins for children. A representative from Warriors in The Workplace, an organization created to connect veteran friendly companies with highly skilled veteran employees, also attended the public test trials at UMPI on Sunday.

Lord hopes to have the Amp Fins ready to market by April 2015.