HARRISON — Pete Alderman can waterski while holding the tow handle with his foot. He can waterski backward … and barefoot.

Not bad for a guy who turns 80 in February.

“I would say he’s definitely an oddity, to be doing the tricks he’s doing at his age,” said Jenny O’Connor of Bridgton. “He skis on this Sky Ski (a hydrofoil) to my kids’ amazement. He is flying so high above the water, it’s amazing. I don’t think there are many teenagers who would try that.”

But without question, Alderman’s favorite waterskiing pursuit is teaching a novice.

Alderman spends the summers on Crystal Lake just north of Bridgton, offering free instruction to anyone who wants to learn how to stand upright on skis. He’s best known for his passion for the sport, having taught an estimated 3,000 to ski over the past 15 years.

Alderman is also a fixture at national waterskiing tournaments in Palm Beach, Florida, where he assists the Delray Beach Ski Club. His buddies include Water Ski Hall of Famer and pro skier Dave Reinhart, who won eight consecutive pro jumping titles and went on to work as a stuntman in movies, including the James Bond thriller “License to Kill.” A few years back, Reinhart and Alderman performed waterskiing tricks on Crystal Lake, when Alderman was only 70.

“I started skiing with tournament skiers right off the bat when I went to the to University of Florida in Gainesville. So I’ve been continuously involved in competitive waterskiing since 1955,” Alderman said.

Peter Lowell of Bridgton, director of the Lakes Environmental Association, became Alderman’s waterskiing partner in Maine 13 years ago. In the summer, they meet at Crystal Lake early every morning when the water looks like glass, ready to offer waterskiing lessons.

“Pete has taught thousands of people. He’s kind of a Johnny Appleseed of waterskiing,” Lowell said. “Often when people are teaching they yank a skier up too hard so they land on their face. Pete wants people to learn right, so it’s a good experience.”

Alderman begins his lesson with land drills, in which students put their feet in the skis and sit back. He hands them the rope and pulls them up, explaining as he does how to let the power of the boat do the work.

“Start in a tuck. Keep your arms straight and let the boat pull you onto your feet,” he instructed a novice two weeks ago.

If it’s done wrong, he sits them back down and has them complete the drill again until mastered.

“That’s it. Now you’re ready to waterski,” he said once the drill was a success.

Alderman believes learning to waterski is made more difficult by starting off the back of a boat. So he begins his water lessons on the long metal pipe, called a boom, that juts out the side of his boat. Skiing off the side is easier because there is no wake. And Alderman can provide direction just a few feet away.

Once his student has mastered skiing while holding the boom, he moves them to a short rope off the boom. Once this is perfected, it’s on to the long, 60-foot rope off the back of the boat. For this, he instructs from the stern using hand signals.

Skiing off a long line is not as easy. Alderman is patient. He drives the boat slowly at first. He says his greatest joy in the sport is helping others experience the wonder of gliding over water.

Lowell said each summer Alderman teaches the association’s milfoil crew, who clean nearby lakes of the invasive water plant.

“He taught my oldest when she was 6. He’s very patient. He kind of takes the fear out of it,” said O’Connor, the association’s membership coordinator.

After any lesson, Alderman preforms a demonstration, which is his understated way to say: It’s show time.

“I’m not that good. The guys I ski with in Florida are good. I just drive the boat for them,” he says modestly.

Be that as it may, he can perform up on the bouncing “air chair” set on a 3-foot-long pole set on blades that skim the water.

This last stunt is usually his finale, but he’ll do it three or four times, each time crashing from his high perch while moving at speeds of 40-to-50 mph. It’s a painful way to wipe out, but each time Alderman does it only makes him smile.

“It’s a great sport. It’s a lot of fun. And it’s the kind of thing you can do until you die,” Alderman said with a wide grin.