Winterizing Your Boat - Sailors for the Sea

Winterizing Your Boat

By: Jessica Wurzbacher, MSc | December 1, 2011

A boater’s least favorite time of year is approaching, the weekend when you give up your aquatic existence and haul your boat out of the water, resigning to several land-locked months ahead and get ready to deal with the impacts of frozen water!

Boat Cleaning 

The forgotten bottom! Probably the last thing on your mind as you enjoyed your cocktails at sunset on a warm summer evening. Once hauled out and sitting like a duck-out-of-water, cleaning is going to be one of your first tasks. Try to use natural cleaners, e.g. lime juice, borax or baking soda. If these don’t work try biodegradable soaps, but use them sparingly. If you plan on pressure washing, find a designated “wash pad” or place a tarp under your boat to catch any debris. You should never clean your boat with solvents while on the water or wash engine parts near the water.

Invasive Species

Once out of the water you should perform a visual check of you hull and remove any clinging plant life or debris. If you plan to move you boat to different waters then these hitchhikers can threaten the natural environment and cause significant economic damage. Rhode Island does not currently have specific regulations regarding cleaning boat motors or hulls to ensure that they are clean of alien invasive species. Some serious offenders in the northeast are; Zebra mussels (Dreissena polymorpha) and “quagga mussels ” (Dreissena bugensis) , Eurasian Water Milfoil (Myriophyllum spicatum) and Japanese shore crab  (Hemigrapsis sanguineus).


As water freezes it expands, this expansion can cause parts to crack and damage. It is therefore important to run antifreeze through your engine before the temperatures drop. For the best protection, drain out as much water as possible and use safe non-toxic marine engine antifreeze that contains propylene glycol. It is usually pink, but can come in other colors (purple, orange, blue) that offer increased freeze protection. Never use automotive antifreeze (ethylene glycol), which is toxic to the environment. Do not dilute the antifreeze.

You should also add non-toxic anti-freeze to heads and septic holding tanks. Never use engine anti-freeze in a freshwater system. You may also need to add some eco-friendly antifreeze to your bilge water. To winterize your fuel and avoid excess condensation, top off your fuel and add a winter stabilization eco-friendly fuel additive.

Proper disposal of oil

Winterizing your engine will create quarts of waste oil. Never dump oil, or other chemical pollutants down the storm drain. Most storm drains go directly to our waterways where oil and paint can kill fish, birds and other wildlife. Collect these fluids and take them to a designated waste oil collection tank at your marina or gas stations oil recycling program. Remember to have a supply of absorbent materials to catch any drips.

Bottom Paint

A boat that spends considerable time in the water is susceptible to “fouling” as marine organisms colonize its hull. In extreme cases this fouling can significantly reduce engine performance and lead to increased fuel consumption. Antifouling paints are therefore important to keep up your boats performance and maintain an efficient engine. These paints commonly contain copper, a toxin, designed to leach slowly into the marine environment, preventing any organism adhering to the paint by poisoning the settling organisms. However, the harmful effects from copper can also be felt further afield than simply on the hull of your boat, and other unconnected marine life can suffer from passive leaching and abrasive hull cleaning. Copper is toxic to aquatic organisms, such as filter feeders (e.g. mussels) and damages larval stages of aquatic invertebrates and fish species. There are currently no restrictions in place on the use of copper hull paints in the United States, but Sweden and the Netherlands do already have strict regulations on the use of copper-based paints on recreational vessels. Luckily there are now some new eco-friendly marine bottom paints on the market. These include zinc formulations (e.g. Epaint Ecominder), organic formulations (e.g. Petit Paint Ultima Eco – contains Econea and Zinc Omadine) and non-biocide coatings, such as epoxy and silicone formulations.

Epaint’s Ecominder is a water-based, zero-VOC (Volatile Organic Compounds), copper-free bottom paint designed for fresh and low fouling salt water environments. ePaint Ecominder is compatible over most existing bottom paints and is much safer and easy to apply. If that’s not enough, it’s also tried and tested; ePaint Ecominder was rated “Good” at 8 months by Practical Sailor magazine in the October issue and recommended as an alternative bottom paint option by the Port of San Diego. This paint works by relying on sunlight to create hydrogen peroxide to deter the settling of hard shell growth on the hull. Ecominder contains 4.8% Zinc Omadine, an algaecide that rapidly degrades once leached from the paint into non-toxic compounds. Zinc on average is 8 times less toxic to aquatic organisms than Copper and most traditional bottom paints contain 25 to 75% cuprous oxide by weight. There is more zinc found in sacrificial boat anodes than in a coat of Ecominder and more Zinc is actually released from washing boat bottoms with traditional copper-based paints than ePaint.

These paints are just as effective at keeping your hull clean, and so much better for the marine world that sustains your boating pleasures. Petit Paint’s Ultima Eco contains Econea and Zinc Omadine, it has been shown that their paint containing 6% Econea biocide is as effective as paints made with 50% Copper. The Environmental Protection Agency’s has conducted an extensive review of “Safer Alternative to Copper Based Anti-fouling Paints for Marine Vessels” which can be downloaded on the Port of San Diego website.

You can also help reduce toxin levels in the water by using non-abrasive hull cleaning techniques to prevent excessive paint discharge and removal of the bottom paint.


Shrink-wrap provides a strong outer layer of protection for you boat, keeping moisture, pests and strong winds from damaging the interior and exterior of your boat. It is an economical alternative to inside climate controlled storage. This polyethylene plastic shrinks tightly around an object and contains UV protection and Ethyl Vinyl Acetate (EVA) to keep it supple in freezing temperatures. But what do you do with it once the snow melts and the warm spring weekends start to beckon you out on the water? Shrink-wrap can be recycled, it should be separated from other trash and ropes, tie-downs, zippers or plastic vents should be removed. You should also try to recycle any leftover scraps too. One alternative is to have reusable canvas covers made, this also allows you to work on your boat over the winter and excess moisture and mildew is less of a problem due to better ventilation from the material.

Clean Marinas

Boat US has created a list of certified “clean marinas” to make it easier to protect the environment. Green winterizing becomes easier when you support a certified Clean Marina and support these businesses who have voluntarily adopted environmentally friendly practices. 23 states now have Clean Marina programs that follow established environmentally friendly practices to help them minimize their environmental impacts. For a boater, this can mean more grassy areas, convenient pump-out stations, plenty of trash cans and recycling bins and many other amenities that not only help keep the waterway clean, they make your time at the marina more pleasant. Find a clean marina near you.

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