Photo by Benjamin Klaver on Unsplash

Two scientific studies of regular boats vs. wake boats have quantified the impact of various boat types on lake beds and marine vegetation. One study in Wisconsin was conducted on Lake Beulah in East Troy. The other study in Minnesota took place on Lake Minnetonka.

What is Wakeboating?

Wake-enhanced boating is a new and interestingly popular form of water sport. It involves use of a power vessel equipped with water filled ballast tanks to increase its displacement and create large waves for surfers or tubers to ride. These waves are often 3 feet high allowing the surfer to follow the boat without a tow rope.

Wisconsin study shows damage when close to shore

In the Wisconsin study, Terra Vigilis Environmental Services studied conditions on Lake Beulah in East Troy, where as many as 40 wake boats were using the lake on summer days causing shoreline erosion, disappearing weed beds, and the potential for transferring invasive species through ballast water discharges.

The study had three phases, and used submersible drones, cameras, sensors, and scuba divers. Ski boats, pontoon boats, and jet boats were also tested. There are rules in some states that require wake-enhanced boats to stay at least 200 feet from shore, but there are no rules in place in Wisconsin.

The recommendations from the study are that wake boats in surf mode must operate 500 feet or more from the shoreline which produces the same waves as a traditional boat on plane 200 feet from shore. Wake boats disturb the bottom to depths of 25 feet.

Read the Terra Vigilis Environmental Services study.

Minnesota study furthers findings with wave data

In the University of Minnesota study, seven different boat types were tested ranging from deck boats to bowriders to wake boats. The research study measured bow and stern pressure waves, transverse waves, and propeller wash using bottom mounted acoustic-based velocity sensors at four water depths (9, 14, 16, & 27 feet). They also collected water quality samples, used underwater and aerial videos, and took lakebed sediment samples.

Their findings were that bow and stern pressure waves are the primary cause of lifting sediments from the lake bottoms. Much of that depends on the mode of travel, e.g., planning, slow cruising, or wake producing.

When wake producing, boats should operate in at least 20 feet of depth of water, and avoid areas of the lake which have significant aquatic vegetation.

Read the University of Minnesota study.

Reccomendations for Wakeboaters

While Wisconsin currently has no specific rules, the study recommends that wake boats in “surf mode” should

• operate 500 feet or more from the shoreline,
• in water at least 20 feet deep.