Update to Boat Owners Regarding Aluminum Pontoon Corrosion Reports
Dear Canyon Lake Boat Owners,
We would like to provide an update on an issue that has recently been brought to our attention and is of importance to many boat owners in our community. The Canyon Lake POA has received multiple reports of corrosion occurring on aluminum pontoon boats. Based on the information gathered so far, these reports appear to be most prevalent in marinas where multiple boats are docked and moored in the water for extended periods of time. There are no reports of any issues with fiberglass boats.
At this time, the cause, or causes, of this corrosion have not been definitively determined. However, corrosion which naturally occurs over time can be accelerated in the presence of stray electrical current, which may result from non-marine automotive battery chargers, or other faulty electrical sources, including without limitation, extension cords, etc., located on docks or nearby structures.
What Has Been Done to Date
The Canyon Lake POA has reviewed water quality data and treatment records from the 2025 golden algae lake treatment, including post-treatment water sampling. This treatment was recommended, approved and applied in collaboration and consultation with EVMWD, GEI, LESJWA, the applicator, and the algaecide manufacturer. The treatment was applied under EVMWD’s state permit, and the water district also partnered with us to pay for that treatment. Records confirm that the chelated copper algaecide applications were conducted within prescribed dosage levels, with some variation depending on lake location.
The Canyon Lake POA inspected our rental marina after receiving reports of corrosion. While no significant stray electrical currents in the water or faulty devices or grounds above the water were detected at the time we inspected, we did discover that when privately owned battery chargers were disconnected from the outlets on the dock, some minor voltage leakage above the docks was significantly reduced.
In consultation with licensed aquatic management professionals from GEI and Elsinore Valley Municipal Water District (EVMWD) and the applicator, we have confirmed the specific vessels that were used to apply the algaecide treatment have not experienced corrosion. These treatment boats are exposed to the highest concentrations of the type of algaecide used to treat the golden algae in 2025, and other algaecides, on a continuous basis at water bodies state-wide, and have not shown any of the corrosion being reported in Canyon Lake.
After receiving reports from concerned boat owners, the Canyon Lake POA immediately consulted with scientific experts to assess potential contributing factors. While service providers reaffirmed that treatment levels were within allowable limits, additional lake water samples were collected and controlled experiments were conducted to attempt to replicate the reported corrosion conditions.
Galvanic corrosion can occur on bare aluminum surfaces—particularly where scratches or exposed metal are present—during extended exposure to lake water conditions with elevated pH and salinity, combined with the presence of dissimilar metals and an electric field. Under these conditions, corrosion can begin to appear as small white nodules on untreated and scratched, raw, aluminum plates.
Testing is currently underway to determine whether the presence of sacrificial zinc, magnesium or aluminum anodes prevents or mitigates these effects, and whether stray electrical current can accelerate this reaction.
Recent lake water sampling also indicates that residual copper levels have decreased significantly.
Current test results indicate that raw lake water samples from mid-February 2026 do not exhibit this galvanic reaction on aluminum plates in the lab, suggesting that today’s lake water is not able to reproduce this reaction.
What Boat Owners Can Do
If your pontoon boat remains moored in the water continuously, we recommend periodically inspecting the pontoons below the waterline for early signs of corrosion. Early indicators may appear as rough bumps or nodules on the aluminum surface.
If you are able to lift your boat from the water, check for:
- White nodules on the aluminum surface
- Rust-colored spots or pitting in the aluminum
- Any deterioration or unusual wear patterns on the pontoons
Importantly, boat owners should also inspect the condition of the sacrificial anodes on their vessel. If the anodes appear heavily crusted, coated or otherwise corroded, they may require cleaning with a wire brush, or replacement.
Other suggestions include:
- Use only Marine-specific battery chargers
- Have the electrical system at your private dock inspected for proper grounding and stray electrical current
- Consider applying protective coatings (pontoon specific products, wax or epoxy, etc) on a regular basis
- Replace pitted or damaged sacrificial anodes with magnesium or aluminum, which is preferred over zinc for freshwater boats.
If your boat shows signs of corrosion, we recommend consulting with a qualified marine or boat maintenance professional for inspection and remediation guidance. Additionally, please contact the Canyon Lake POA and provide the following information if possible:
- Location where the boat is moored
- Age and model of the boat
- Current condition of the pontoons
- How long your boat has been in the water
- Presence of electrical outlets on or near the dock
- Whether a battery charger is used while the boat is docked
- Condition of the boat’s sacrificial anodes
Next Steps
The Canyon Lake POA will continue to investigate the potential causes of these conditions through ongoing sampling and controlled testing for further analysis, recommendations for remediation, and an understanding of any potential long-term impacts.
We remain committed to transparent communication with the boating community and will provide another update as additional information becomes available, or within the next 30 days, whichever occurs first.
Thank you for your attention to this matter and for your continued cooperation as we work to better understand and address these conditions.
Sincerely,
Canyon Lake Property Owners Association