propeller with growth

It doesn’t take a rocket scientist, or a marine engineer for that matter, to understand that where we have a motor yacht, you usually have water. And, where you have water, you have a cacophony of plants and assorted sea creatures, all of which want to make the external surfaces of your yacht their home. Marine growth can be a problem anywhere it occurs on your boat, but it can be particularly damaging to your propellers. A propeller that gets significantly fouled by weeds or other marine growth can lead to engine failure or all manner of other problems.

Propeller Problems

Marine flora and fauna can turn your props from the sleek shiny metal they are supposed to be to a shell-filled, weed-entangled, “furry,” mess! A propeller laden with marine life cannot possible work efficiently. If left untreated, a propeller covered in sea growth can eventually cease working all together!

Leaving marine growth unattended on your boat’s propellers can damage more than your motor yacht. Believe it or not, as you travel, you may disrupt delicate marine eco-systems by introducing invasive species that have been living on your props!

So what can be done about marine growth? The solution is, anti-fouling paint.

Marine Growth on Bottom of Boat

Anti-Fouling Paints and Coatings

Basically, an anti-fouling paint or coating is designed to inhibit marine growth. These paints contain either natural or chemical biocides that specifically target barnacles or other marine life that tend to affix themselves to your yacht. There are anti-fouling paints that are specifically made for propellers, as opposed to bottom paints.

How often you use your yacht and where it is docked will determine the kind of prop paint you need, and how often your propellers need to be painted. A motor yacht that is used every day, may not need to be coated at all, or rarely, as the constantly spinning propellers tend to make it difficult for growth to take hold. A yacht that is sitting at the dock more often, is more likely to develop propeller growth.

Removing growth from prop

Dealing With Marine Growth

Prevention is the key to discouraging marine growth. Ideally an anti-fouling paint should be applied to the props before the boat has even spent any time in the water. This should retard any significant growth for at least a year or more. After that, if your boat is periodically recoated, you should not have a problem with marine growth.

Once marine growth has been allowed to take hold, it is a three step process to remove it, and to prevent its recurrence.

First, the props will need to be sandblasted to remove the existing growth, and create a clean surface upon which the anti-fouling agent can be applied. Then, before the actual anti-fouling paint is applied, your service technicians will apply an epoxy resin that the paint needs to adhere to. Finally, the anti-fouling paint is applied. The most common biocide in these paints is copper. As your propeller spins, the copper slowly leaches out, and inhibits the growth of barnacles, weeds, and other critters. Since the coating is actually designed to wear over time, you probably will have to repeat the process in a year to 18 months.



Operating a motor yacht can be costly. You can reduce your expenses, and avoid costly repairs by keeping her well maintained. On Demand yachting from FYM can help. If you would like to learn more, or if you have any questions or comments about this blog post, do not hesitate to contact our Yacht Management specialists, or call us at (855) 318-6328.