Boating: Barnacle Removal Tips

If barnacles are a problem on your boat, here are some tips and instructions on how to remove them.

What are Barnacles?

Barnacles are living creatures that are members of the crustacean family. They are related to shellfish such as shrimp and crabs. They thrive in salt water throughout the temperate regions of the world. Removing barnacles from boats is a difficult problem for boat owners, who spend countless hours and money on barnacle removal. When barnacles and other creatures attach themselves to a boat's hull, it is called fouling.

As juveniles, barnacles swim freely in the ocean, but as they approach adulthood, they attach themselves to a substrate and then form a shell. Once barnacles are attached they form large colonies where they remain for the rest of their life spans, usually three to five years. Wood, fiberglass, aluminum, and metal substrates are all fair game to the barnacle.

The shell is the only part of the barnacle that is visible to the eye. Barnacle shells are made of a calcareous substance similar to limestone. The barnacles secrete a cement-like substance, which they use to attach themselves to the host substrate. The shells are very sharp, and even when scraped off, the cement-like substance forms a series of overlapping plates that are extremely durable and difficult to remove.

Why Are Barnacles a Nuisance?

Large colonies of barnacles lower boat speeds by increasing their resistance in the water. In addition, other fouling organisms also get caught up in the barnacles contributing to the drag. Boats expend more energy and use more fuel, in some cases as much as 30 to 45% more.

How do I Remove Barnacles?

Barnacle removal usually takes place when the boat is out of the water and in dry dock. Divers can also remove them while the boat is in the water. Removal methods depend on the size of the barnacles. For very small barnacles, a scrubber might remove most of them. If the barnacles are bigger, but there are not many of them, try using a plastic scraper or a metal one with a dull edge so you don't scrape off too much paint also.

For large colonies or larger sized barnacles, it is best to use a power washer. Although power washing is expensive, it may be worth your while. Take the boat out of water and let it dry out for several weeks, if possible. Direct the spray from the power washer parallel to the hull. Do not spray the barnacles' head on. This should remove most of the shells.

To remove the plates that are left behind, try applying hydrochloric acid or a commercial hull cleaner, and then use a scraper. Wear gloves and be careful not to let the acid splash on you. When you have removed as many of the plates as possible, use a lime remover and then wash the boat hull thoroughly.

Barnacles can be prevented from colonizing on boat hulls by applying a paint containing copper or tin, which is toxic to barnacles. Unfortunately copper and tin are also toxic to other marine life. Scientists are working on creating a rubbery or non-toxic plastic substance that can be applied to boat hulls to repel barnacles, or at least make them easier to remove.

© High Speed Ventures 2011