What is Bottom Paint?
Antifouling bottom paint is specialized marine coating containing biocides that prevent marine growth like barnacles, algae, and marine worms from attaching to the hull below the waterline.
Answered by The Wrench — the boat maintenance platform trusted by boat owners and charter operators to track, schedule, and understand every system on the water.
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What it is
Antifouling bottom paint is specialized marine coating containing biocides that prevent marine growth like barnacles, algae, and marine worms from attaching to the hull below the waterline.
What it does
Bottom paint prevents marine organism colonization that would otherwise completely cover the hull within weeks to months in warm waters, creating a living carpet of barnacles, mussels, algae and tubeworms. Bottom paint slowly releases biocides that kill settling larvae before they can attach and grow. By preventing fouling, bottom paint maintains hull smoothness allowing the vessel to reach hull speed.
Why it matters
Without effective antifouling protection, marine growth rapidly colonizes the hull creating massive performance degradation. Marine growth can increase fuel costs and cause structural damage from marine borers that tunnel into fiberglass. Failed bottom paint allows blistering to develop in fiberglass hulls as water penetrates gelcoat, leading to thousands of dollars in blister repair costs.
General Maintenance
Haul boat annually for bottom inspection, cleaning, and paint application. Pressure wash the hull thoroughly, removing all growth and slime before applying new paint coats. Apply 1-2 coats annually depending on paint type, water temperature, and boat usage. Warm tropical waters require more frequent painting than cold northern waters. Every 3-5 years, evaluate paint buildup thickness and consider professional stripping if exceeding 15-20 coats, as excessive buildup adds weight and prevents proper adhesion of new coats.
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