This study focused on characterizing the hydrodynamic phenomena produced by a moving powerboat and investigating the impacts on the water column beneath the boat and at the lakebed.
The motivation for this field-based research study was the need to better understand the environmental impacts within the water column and at the lakebed as different types of recreational powerboats traverse under their typical modes of operation. The objectives of the study were to: 1) clarify and define the various hydrodynamic phenomena that are created by a recreational powerboat in motion, and how these phenomena vary with water depth and mode of operation, 2) investigate the depth of penetration and duration of emission gases (e.g., engine exhaust bubbles), 3) investigate the water column velocities and depth of penetration of the bow, stern, and transverse waves and their potential to resuspend lakebed sediment, 4) Investigate the propeller wash velocity and depth of penetration, and the potential to resuspend lakebed sediment, 5) investigate the effects of repeated boat passage on thermal stratification and mixing in the water column, 6) capture underwater and aerial video of the hydrodynamic phenomena and any subsequent impacts (e.g., sediment resuspension).
This study generated a wealth of data that we used to developed recommendations on the minimum operational depth that recreational powerboats, under typical modes of operation, should maintain to minimize impacts to the lakebed.
The final report was published in July 2025. Links to the report and data (including videos) are below.
A brief Project Summary of Phase II and Frequently Asked Questions are available below:
The Phase 2 research report involved collecting underwater and aerial drone footage. These data allow us to see the hydrodynamic phenomena created by the various powerboats that were tested in this study, and their impacts on the water column and lakebed.
The videos are now available on the SAFL Youtube Channel
The videos can also be downloaded here
We presented a webinar on Tuesday, August 26, 2025. The full recording is available on the SAFL Youtube channel or by clicking below.
Have a question or comment about the Phase 2 report? Send us an email: healthywaters@umn.edu