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A science teacher enlists the help of his trusty pupils to hunt shipwrecks, while teaching valuable lessons along the way.

Jean-Marc Perreault goes to great lengths to reach his students. Over his 27-year career, the science and technology teacher has built a space shuttle cockpit simulator in his Lavaltrie, Quebec classroom as well as an observatory that lets students take pictures of planets and even other galaxies.

Perreault also loves to dive and boat on the St. Lawrence Seaway. He owns a Rosborough RF-18, a rugged little ship with a high bow and pilothouse. After purchasing a new sonar, he thought of an innovative way to teach his students about sound waves and vectors.

Jean-Marc Perreault (leaning on hard top) and his students aboard "La Petite Calypso".

Jean-Marc Perreault (leaning on hard top) and his students aboard "La Petite Calypso".

“I bought the most affordable Raymarine sonar with DownVision to navigate the shallow waters of the St. Lawrence,” he said. “When we got to an area with a shipwreck noted on the chart, I wanted to try to find the wreck just for the fun of it. I was dumbfounded by the amount of detail returned by that little sonar. Something in my brain just went click, and right there and then I knew I finally had a way to experiment with textbook theory about waves and sound with my students.”

By using the boat, high school students can instantly see how sonar waves reveal what is hidden beneath the surface of the water, and how frequency influences the image’s detail. He pitched the idea of going out in search of wrecks to his physics students, and 11 of the 16-year-olds signed up. Perreault took four to five students out each weekend from September through the end of October, and what they found surprised them all.

“It can take us an hour to get to a search area at full throttle, and then we mostly idle around scanning for wrecks,” he said. At first they went to areas with known wrecks. “While slowly idling from one wreck to another we found our first unmarked one, and then another. We found 10 unmarked wrecks, some of them quite large, and hope to find even more in what has revealed itself to be a forgotten graveyard of wooden ships used for both World War efforts.”

To identify the wrecks, his students conducted research and turned to social media to connect with other wreck hunters. Perrault even dove on one large wreck they discovered. The propeller was still intact, and he noted traces of a fire on board, but they’re still stumped as to the ship’s identification. While the history of the wrecks is interesting, the technology used to find them is what really stands out.

The class used the winter months to build what they call a “tow fish” device to obtain better sonar imagery and even video.

The class used the winter months to build what they call a “tow fish” device to obtain better sonar imagery and even video.

“There is a very strong link to be made between sonar images and medical imagery, especially medical ultrasound,” he said. “Making something visible on a screen that otherwise would remain invisible to the eye is quite exciting. Many of my students will have careers linked to healthcare, and this activity may reveal in them an interest for image analysis.”

While the educator is more than happy to share his ideas with other teachers, he says we can all do our part by taking kids out on the water and using electronics to get them interested in what lies below the surface and thinking about other ways this technology could be used.

Working with teens on the boat has also spurred a sense of camaraderie. He named his vessel La Petite Calypso, after Jacques Cousteau’s famous research vessel, and even bought red wool caps for his crew. He’s also welcomed students who harbor special needs and watched them blossom.

“I made a strong point about them being part of a team,” he said. “Some of these students are brilliant but have ASD (autism spectrum disorder) traits or other difficulties; they are the ones that became the most interested in the project. One of the students, the very quiet type, barely spoke to me before the project and has opened up substantially. The parents are really happy for their kids and grateful.”

With the help of Raymarine, Perrault upgraded the electronics suite on his vessel and is eager to find more wrecks with his students. “As soon as the river is free of ice and dangerous debris, we will be at it again even more so, because the next time we go out, our efforts might help find the remains of a missing soldier,” he said. “We can make history while searching for history. That is awesome for me.”

This article originally appeared in the Summer 2021 issue of Power & Motoryacht magazine.