FAQ

The 2022 study by Marrs et al. at the MN St. Anthony Falls Lab is frequently cited by groups opposing wake boats despite the fact his study was not novel, and was never published in a scientific journal, nor did it follow peer review protocols.   This study suffers from severe flaws in data collection and analysis.  It fails to adhere to standard scientific conventions. This work does not rise to the level required for policy decisions.  Refer to the section labeled St Anthony Falls study of this website for a white paper that discusses the key issues that undermine its credibility. St Anthony Falls 

ALL boats transfer AIS. We all should be concerned about the transfer of AIS between lakes. In 2008, Notre Dame conducted a study assessing boating traffic in northern Wisconsin and the Western Upper Peninsula.  The study found that most boaters fish in the same small number of lakes. However, about 30% of boaters move among lakes, sometimes visiting multiple lakes in a single day.   And boaters who moved between unconnected lakes often (more than once every 5 days) were categorized to be at a greater risk of transmitting AIS (Witzling et al., 2016).  In contrast to fishing boats, most wake boats are used primarily on their owner's home lake.  Also, while efforts are increasing to inspect and clean boats and lakes to efficiently prevent AIS from spreading, only 56% of boaters and approximately 80% of trained professionals successfully removed all AIS during a controlled study (Angell, 2023).

While AIS is a valid concern, comprehensive policies should target all watercraft, and efforts should be directed toward improving sanitization and certification practices rather than focusing solely on wake boats.  

No. The wake boat is designed to create a surf wave on one side or the other, depending on surfer.  If the surf area requires a circular pattern, like a lake, it's intuitive to "curl" into the surf wave, meaning the majority of the time the surf wave should be sent to the center of the lake.

Also, most of the newer boats have several wave profiles.  A younger or smaller surfer will rarely surf the "max" wave setting, using the smaller wave settings.

Finally, the non-surf wave or washed-out wave will have a reduced height and energy compared to the surf wave.

The science behind waves has remained consistent for over 40 years of study. The fundamental nature of waves is governed by the properties of water and gravity—constants that are unlikely to change. 

Emphatically - no.  Your information is private, period.

Currently, due to our structure any donation is not tax deductible.

It should be noted that members of SWSC are all volunteers and do not receive any payment.  The funds are used for research, communications and printed material to help educate the public.

Please go the the Discussions Tab under Invasives Species. Wake boats are not unique.  You also can’t inspect the residual water in any  stern drive and they have been show to trap 85% more water than ballast tanks. Impact of AIS 

Wake surfing regulations should be managed at the state level rather than by individual towns to ensure fair, effective, and scientifically backed decisions across Wisconsin waters. Restricting someone’s access to these waters under the Public Trust Doctrine should only happen with a compelling and undisputed rationale—one based on extensive, expert-led scientific investigation that provides clear evidence of necessity.

Local town boards, often staffed by part-time members with limited budgets, simply do not have the resources to engage with the specialized experts needed to develop high-quality, evidence-based condition reports. Without the expertise and funding to conduct these comprehensive studies, town-level decisions risk being based, not on sound science but on incomplete or anecdotal evidence often influenced by groups with an agenda. 

Additionally, watercraft regulations must be applied uniformly across the state to avoid a confusing and fragmented patchwork of local rules that would be challenging to enforce and difficult for the public to follow. A consistent statewide approach ensures fairness, clarity, and compliance, benefiting all who enjoy and protect Wisconsin’s waters.

Wake boats operate at ~11 mph vs ski boats that go >30 mph.  Ski boats cover 3 X the distance of a wake boat.  Even pontoons tubing go 2 X as far.  At 200 feet the waves of a wake boat are the same as a water ski boat at 100 feet but the ski boat will travel 3X as far.  

Any large boat with sufficient weight will generate similar waves.  Pontoon and other watercraft manufacturers are also developing product to allow wake surfing. 

Boat wakes and shore erosion have been studied for over 40 years. Research consistently shows that shore erosion is primarily caused by factors such as ice, runoff, changes in lake levels, natural wave action, and development—not by boat wakes. At 200 feet the waves impacting a shore have the same total energy as a fishing boat or ski boats at 100 feet and less than a 20 mph wind blowing over a mile.

The form of energy is indeed important but wind and recreational boat wakes are similar.   Statements like you cannot compare boat wakes refers to large  vessels. Waves have intrinsic characteristics whether they are created from boats or wind.   Comparing the height, period and duration allow direct comparison of wave energy.  A 20-mph wind blowing over a mile will create a 7.5’ tall wave with a period of ~1.8-2 seconds.  A wake boat 200 feet from shore will generate 45-60 seconds of waves with a maximum height of 8-10” and a period of 2 seconds.  These waves have similar energy, consequently, wake boat waves will not present a substantially different form of energy to the shore. Cox and McFarlane (2019) conclude “Wave wake studies are inevitably a study of orders of magnitude and not small percentages”.   While the wave energy and period for wake boats and wind waves are similar, the total energy a shoreline receives from wind is 20X or more higher since wind wave impact every 2 seconds vs. a packet of boat waves which only last 40-60 seconds.  To match the energy of a 20-mph wind over a mile requires a wake boat to pass a shoreline every 60 Seconds.

This is one extreme case from a boat that is overloaded with more ballast than the factory configuration, operating in deep water that is not typical of most Wisconsin lake shorelines.  That same study showed that the wave is 9” 200 feet from the boat in shallower water.  No other study found a 16” wave.  Five other studies report 8-10” 200 feet from the boat.   

The energy of the initial wave right at the boat is higher than other boats but wave energy degrades rapidly as it breaks up into multiple smaller waves.  The larger the initial wave the faster it attenuates.  At 200 feet the max wave energy of a wake boat is similar to fishing and ski boats. The SAF study claims at 100 feet the waves have 3-9 time more energy, but their energy calculations are 2-8 times higher than more experienced researchers demonstrating their analysis is flawed.

The definitive study on lakebed disturbance was Dreager, et, al in 2022.  They measured the suspended solid, phosphorus, SiO2 and nitrates.  The results conclusively showed that all boat types can disturb lake beds in 3-5 feet of water, but once wake boats operate at depths of 10 feet or greater, lake sediment does not resuspend. 

Experimental studies of water velocity from propeller jets further validate wake boats do not disturb lake beds at >10 feet. Raymond & Galvez-Cloutier) measured water velocities of 0.2 mph near 10 feet.  This is too slow to move sand but is near the threshold to mobilize small silt.  However, the actual diver did not observe any impact. A 2003 study by Anthony and Downing examined water velocity at depths of 4, 5, and 6 feet from a 150-horsepower boat operating at various speeds. Key findings include:

         •Maximum water velocities at these depths occurred at boat speeds of 6–8 mph, significantly below wake surfing speeds.

         •Water velocity dropped sharply between depths of 4 feet and 5 feet.

         •Water velocity decreased rapidly when boat speeds increased from 8 mph to 11 mph.

The water velocity required to displace small silt particles (50 microns, or 0.050 mm) is 12 cm/sec  (0.28 mph) while moving larger sand particles (0.3 mm) requires velocities of ≥25 cm/sec (0.56 mph). At 11 mph—typical for wake surfing—St .Anthony and Downing recorded water velocities of ~16 cm/sec at a depth of 5 feet. At greater depths, viscous dissipation further reduces velocity. Beyond 6 feet, water velocity from a propeller falls below the threshold to move even the smallest silt particles.

Data from Wisconsin lakes do not support claims that wake boats increase turbidity and algae blooms. The WI water quality data is excellent and shows no deterioration in lake clarity since wake boats were introduced.

An Indiana study confirmed that prop wash does not impact lake beds at depths of 10 feet or more. If vegetation is present, it would further reduce the depth at which sediment disturbance could occur.

200 feet from a wake boat the waves are very similar to what the shoreline experience naturally.  The waves are not significantly different.  The wave heights  for wake boats are 8-10 inches vs 7.5 inch for a 20 mph wind, and the periods are both around 2 seconds.  

This study is not consistent with prior studies that find wake contribute <5% of the energy a shoreline experiences.  Even the authors admit their findings are not consistent with prior work and offer no explanation.

The Study published by Dreager in the Proceedings of the Indiana Academy of Science definitely shows in >10 feet of water there is no sediment resuspension. See Scientific Analysis of Wake Surfing effects on Lakes under Documents tab. 

Adding ballast increases the size of the initial wave at the boat, but larger waves decrease quicker.  By 100 feet the wave produced by a boat with and without ballast are the same.  (SAF, McFarlane) 

This is true when wind and wakes have significantly different characteristic and were meant to address attempts to compare the wake from large ferries to wind.  In WI the wind and boat wakes ARE similar so comparing energy is reasonable.  

Wake boats are not the only boats that operate with bow up attitudes.  There are no records of safety incidents for wake boats but there are many for PWC, fishing and pontoon boats.   The Coast Guard has certified these boats are safe to operate.  Inattentive driving is an issue with any boat. 

The vast majority of the time, a wake sport will only use ballast while doing the activity where ballast is needed, like wake boarding or surfing.  There is no reason for a wake boat to keep it's ballast while normal boating or trailering.