A new study, funded in part by the National Marine Manufacturers Association and written by two Mercury Marine employees and the principal in a marine consulting firm in Washington State, concludes that “if a wake surf boat is operated 200 ft from shore and in at least 10 ft of water, the environmental impact is minimal.” But the study is food for thought on whether our current regulations are adequate for minimizing environmental harm from boat wake and prop churn.
Wake surf boats are a cousin of wake board boats. Both use ballast to create a large wake at lower hull speeds. The difference between the two is that wake surf boats are meant to allow the person on the board to surf the wake without being pulled along by a towline. Where wake board boats operate at 20-22 mph, wake surf boats churn up their waves at 10-12 mph. In either case, the point of these designs is to create a big enough wake from a small powerboat for people on boards to have fun.
People not on boards however aren’t always happy to have wake surf or wake board boats around. Deliberately large wake is often not welcomed by other users of a body of water, including paddle boarders, canoeists, and kayakers, and shoreline owners have been concerned (as they are with any boat wake) about the possible impact of such activity on shoreline erosion.
The authors used a lot of math and computational fluid dynamics to create wake scenarios. You can wade through the calcs yourself, as well as their follow-up field obersvations, but the bottom line is their conclusion that wake surfing boats can be of minimal environmental impact if they stay 200 feet from shore and in 10 feet of water. The depth figure is important because the authors state that to reduce turbidity, “motor craft should not operate at planning [sic] speeds in water depths under ten feet.”
At the moment, there are no regulations in Canada that limit the operation of motorized vessels according to water depth. And the authors make a truly strange claim that suggests planing boats in Ontario are already required to stay well clear of shore: “On large lakes in Ontario, a speed limit is imposed within 100 m (330 ft) from shore of 10 kph (6.3 mph) and 70 kph (44 mph) over the remainder of the lake.” The actual prescription in the Vessel Operation Restriction Regulations of the Canada Shipping Act is that speed is limited to 10 kph within 30 meters (about 100 feet) of shore in the waters of Ontario and in several other parts of the country, with several important exceptions, including the right of ski boats to go faster than 10 kph when steering perpendicular to the shore in getting someone up on their skis. (The other exceptions are a buoyed channel or a river less than 100 meters wide.) I have never heard of a maximum speed of 70 kph. The VORR also contains schedules of water bodies in Canada in which wake boarding (and other tow sports) and wake surfing is restricted or prohibited.
I emailed the lead author of the paper to point out the errors regarding speed restrictions in Ontario. His reply: “I didn’t mean to imply that the restrictions or rules were already in place. I meant to show that certain states, lakes and regions had rules in place as examples or [sic] what has been done and that everyone has the right to enjoy the water.” Well, he did say what rules were already in place in Ontario, and the paper is wrong, and his reply is a reminder that I really do live in a different country. In Canada, there is no concept that “everyone has the right to enjoy the water,” at least when it comes to types of water craft and how they are used. The Canada Shipping Act and the VORR make that pretty clear.