Yes, you should clean your boat every time you use it in another lake or river. And not just your boat! Same applies to paddles, fishing gear, motor. Needless to say, it is even more true for any boat brought to your lake by a visiting relative, friend, guest and, even more important, a renter!
Why? To make sure that our lakes never look like this!
This aquatic plant is called Eurasian Watermilfoil. As the name implies, it is exotic, non-native, and very invasive since it has no predators. It can be found in 40 lakes in the Laurentians. Thank God, none in Argenteuil. It is almost impossible to get rid of, the only defence is prevention.
Hence, boat washing!
Remember these four steps: inspect – drain – clean – dry
Inspection is the most important. If you look carefully, you will probably locate exotic plants or molluscs. Drain to make sure the is no leftover water at the bottom of your kayak, for example. Clean with fresh water and a bit of bleach. Finally, let dry in the sun for a few days.
All this should evidently be done at a good distance from the lake.
Identifying Eurasian water-milfoil is difficult because there are at least five native water-milfoils that, at first glance, look pretty similar to it but are not really invasive.
This Guide (in English) should prove very helpful. eurasian-water-mmilfoil-guide