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LakeQuality

Recreation

Wedge

A deployable underwater foil at the transom that pulls the stern down and shapes the wake, used by Malibu (Power Wedge) and Axis to add wave size and adjust length without additional ballast.

Wedge is a term from limnology — the scientific study of inland waters. The detailed explanation below covers the definition, why the concept matters to lake water-quality interpretation, and how it intersects with the LakeGrade rubric. Reading Wedge alongside the LakeGrade rubric helps make the rubric's structure intuitive — each grading parameter maps directly onto an established limnological concept.

The per-lake pages on LakeQuality always show the specific Wedge value for that lake, so you can move from the general concept to the specific lake without leaving the site.

What It Means for Your Lake

The wedge is a transom-mounted hydrofoil that, when deployed, drops the back of the boat farther into the water to increase displacement and shape the wake. Malibu's Power Wedge III is described as a reverse hydrofoil that shapes and lifts the wave, letting riders define its height, length, and shape; deploying it lowers the stern, and the down positions make the wave face longer and more mellow without losing size. Because the wedge adds effective weight without water ballast, it speeds up wave setup and complements the surf system. Power Wedge III offers six settings plus a Lift Mode that helps the boat get on plane more quickly when speed is set above surf speed.

Frequently Asked Questions

What is wedge?

A deployable underwater foil at the transom that pulls the stern down and shapes the wake, used by Malibu (Power Wedge) and Axis to add wave size and adjust length without additional ballast.

Why does wedge matter for lake health?

The wedge is a transom-mounted hydrofoil that, when deployed, drops the back of the boat farther into the water to increase displacement and shape the wake. Malibu's Power Wedge III is described as a reverse hydrofoil that shapes and lifts the wave, letting riders define its height, length, and shap...

Source: EPA National Aquatic Resource Surveys, 2026.