Study: Larger waves from wakeboats need more distance from shore to reduce size, power

A silver and white wakeboat on the water.
A wakeboat pulls away from a dock in July 2019 on Lake Minnetonka in Mound, Minn. Opponents of wakesurfing believe that the waves created by the boats cause erosion along the lakeshore.
Christine T. Nguyen | MPR News 2019 file

A new study from the University of Minnesota suggests that wakesurfing boats need to stay farther from shore than traditional boats to reduce potential damage from their larger waves. 

The study’s findings, released Tuesday, have been highly anticipated by advocates of stronger regulations for wakesurfing boats.

The sport of wakesurfing — coasting behind a boat with a specially designed hull that creates a large, curled wake — has been growing in popularity on Minnesota lakes, sparking concerns about shoreline erosion and other impacts.

“This is a topic that's become quite of interest for many people in the state, people that own boats and people that use our lakes and rivers,” said Jeff Marr, associate director of engineering and facilities at the university’s St. Anthony Falls Laboratory.  

Researchers from the lab launched the study to analyze and measure the waves created by wakesurfing boats compared to more traditional recreational boats.

In fall 2020, on Lake Independence in Maple Plain, Minn., they used sensors to measure the height of waves produced by four types of recreational boats. They also calculated the power and energy of the waves, and how they changed as they moved toward shore.

Your support makes a difference.

MPR News is made by Members. Gifts from individuals fuel the programs that you and your neighbors rely on. Donate today to power news, analysis, and community conversations for all.

“What we learned is when you operate wakesurf boats in a surfing mode, the waves are two to three times larger than a non-wakesurf boat,” Marr said. “That’s an important number to finally understand how much bigger they are.”

Researchers also found that when the boats are operated in their typical mode, waves from wakeboats need to travel a greater distance — more than 500 feet — to decrease to the same height, energy and power as those from traditional boats. 

While there’s no requirement in state law, Minnesota guidelines recommend boaters stay 200 feet from shore, docks and other structures to reduce the likelihood that their wakes will cause damage.

The findings likely will fuel debate over whether wakesurfing boats should face additional regulations. 

State lawmakers have proposed bills in the last two legislative sessions that would impose limits on how close wakesurfing boats can operate to shore, and prohibit their use on smaller lakes. Those measures failed to pass.

Jeff Forester, executive director of the nonprofit Minnesota Lakes and Rivers Advocates, said he hopes data from the study can be used to develop best practices for boat operators that can be taught through an education and certification program.

“Once we have this information, boaters will know how to operate in a way that doesn't degrade the lake or the river that they're recreating on,” he said.

After the state Legislative-Citizen Commission on Minnesota Resources declined to fund the study, the university raised more than $140,000 through a crowdsourcing effort. Donations came from across Minnesota and states as far away as New Hampshire, Oregon and Missouri.

Marr said the study is the first step to a greater understanding of the waves that boats produce, but there’s more work to be done to understand their impacts. 

In the next phase, researchers plan to study the effects of propeller wash or turbulence caused by boat propellers. They also want to better understand how waves interact with the lake bottom and aquatic vegetation, Marr said.