There are three basic types of covers for boats. Which type you need depends on how you plan to use it. The first type is designed for indoor or outdoor storage out of the water. The second type is designed to protect your boat on a trailer. The last type, a mooring cover, is designed to protect your boat while it is anchored in the water.
If you plan to store your boat indoors in a protected area, you may be able to get away with a lighter weight material, such as 100% cotton or a cotton poly blend. If moisture could be a problem in your storage area, you will need a waterproof or water-resistant coating to prevent moisture damage. Also, if your boat is exposed to sunlight through a window, you will need a storage cover with UV protection.
Outdoor storage requires a heavy duty material, especially if you live in a harsh climate. Choose a cover made from thick, durable material, such as marine polyester. It should be waterproof and provide protection from UV rays. A breathable material allows moisture to evaporate instead of becoming trapped inside your boat, where it can cause water damage. The UV coating resists fading to keep the color of your boat cover as vibrant as the day you bought it.
Don’t let standing water or snow pool on top of your storage cover. The extra weight can cause the material to stretch so that it no longer retains its snug fit. Allowing excessive moisture to pool on top of your cover can also give mold and mildew a place to flourish. These intruders eat away at the fibers of your material and compromise the cover’s protection. With the right care, a mildew-resistant cover will repel mildew, but if you fail to take care of it as recommended, it may not provide full protection as it was designed to do. In order to prevent sagging, use cross braces as support. PVC pipe or homemade braces will do the job just fine.
More durable than your typical storage material, a trailerable cover is made to last through the wear and tear of trailering, including harsh weather conditions and high winds. Use manufacturer-approved tie down straps, not bungee cords, to get a tight enough fit and to avoid damaging your cover or boat. Cinch the straps tight enough to prevent air pockets from lifting and tugging at your boat cover. Allowing it to whip in the wind as you travel down the highway is a sure method of destroying your cover. Tie it down especially tight at the bow to prevent lofting. Tighten as needed on long trips.
A trailerable cover must be made from highly durable material to withstand the wear and tear of road travel. 100% marine polyester is stronger than a cotton poly blend, making it a popular material for trailerable marine covers. Choose a cover that offers a snug fit, such as an elastic hem or drawstring. It should also be weatherproof and protected with a UV coating.
Mooring covers are designed to provide in-water protection for docked boats. These covers must be able to withstand harsh winds and rain and constant sun exposure. Cotton and cotton poly blend materials allow the most breathability to protect from moisture damage during mooring.
For the most versatile and economic choice, look for a marine cover that is approved for more than one purpose, such as storage and trailering. Instead of buying two separate types, you can use the same cover for two different purposes.