Boat Antifoul Calculator

REF: EN-212-MAINTENANCE

Use this tool to calculate the exact amount of antifouling bottom paint required for your vessel. By factoring in your boat's dimensions, hull profile, and the desired number of coats, this calculator determines the wetted surface area to prevent you from overbuying expensive marine paint or coming up short mid-project.

INPUT PARAMETERS
> SYS_UNIT:
> OUTPUT_REQUIRED_PAINT
1.42 US GAL
Estimated Wetted Surface Area: 255 SQ FT

Understanding Antifouling Paint

Antifouling paint (often just called "bottom paint") is a specialized coating applied to the underwater hull of your boat. It contains biocides that prevent marine growth like barnacles, slime, and weed from attaching to the fiberglass. This maintains your boat's performance, top speed, and fuel efficiency while protecting the hull from blistering.

Types of Antifouling Paint:

  • Ablative (Self-Polishing): Designed to wear away gradually as the boat moves through the water, constantly exposing a fresh layer of biocide. Excellent for multi-season use and minimizes paint buildup over the years.
  • Hard Modified Epoxy: Does not wear away. The biocide leaches out of the hard paint film over time. Ideal for fast powerboats, racing sailboats, or boats stored in the water that get scrubbed frequently by divers.
  • Aluminum Safe: Standard paints contain copper, which will severely corrode an aluminum hull or outdrives (galvanic corrosion). You must use copper-free (often zinc-based) paint for aluminum structures.
Pro Tip: Most marine paint manufacturers recommend applying a minimum of two full coats, plus an extra third coat around high-wear areas like the waterline, leading edges of the keel, and the rudder.