Boat Tarps

The most important aspect about choosing a boat tarp is the breathability of the material. If a tarp material does not allow for air circulation below the cover, mildew, mold, and bacteria can develop over the winter when the boat is in storage. Mildew and dry-rot can also result from a plastic or vinyl cover pulled too tightly over the boat. The most common materials for a boat tarp are 100% cotton canvas boat duck, at 10 oz. per square yard, and a 50/50 poly/cotton combination, at 11oz. per square foot. Other materials used in boat covers are Sunbrella, a man-made material of 100% acrylic, and vinyl with denim backing, which prevents the fabric from excessive stretching.

The fabric most ideal for the breathability of a boat tarp is 100% cotton. The downside of a 100% cotton tarp is that the tarp will not last long when exposed to UV rays. A 100% cotton cover will last and work the best when a boat is stored under a carport for the winter, particularly if the boat is stored near water.

The most popular tarp fabric for a boat cover is the 11oz. 50/50 cotton/poly blend. The cotton allows for ventilation in the material but the polyethylene tarp will last longer when exposed to UV rays, so that the boat will not need to be stored under a carport for the entire winter.

Boat tarps can also be made from 100% polyester, which is also used as a trailer cover. The benefits of the material include that it is lightweight, keeps out fine dust, protects from high UV problems, and has a five year warranty. However, the cover does not protect against humidity. In some parts of the United States, where the humidity is always relatively low, this type of cover can be useful. But, in the eastern part of the United States, which experiences humidity with higher temperatures, a 100% polyester cover will not protect a boat sufficiently.

Another option for a boat tarp is Sunbrella fabric. Sunbrella is ideal for custom fit boat covers. The fabric is expensive but the benefits are that the woven acrylic fibers allow the fabric to be water resistant and breathable and that the material has a five year warranty.

Aside from a tarp, protecting a boat during winter months or periods of no usage include making sure water does not accumulate on the cover. Water can put excessive strain on the tarp materials, as well as allow for organisms to accumulate. In the case of cotton, organisms in water can eat through the material, causing it not to last as long as it should.