Boat Cover Fabrics 101

Fabric Descriptions

Sunbrella® Marine Acrylic

10-Year Limited Warranty

A premium 9.25 oz. solution-dyed acrylic with lasting color, strong UV performance, water resistance, and the breathability needed for marine storage. Sunbrella® is the heavier of the 2 fabrics offered here and carries the longer limited warranty.

Sun-DURA® Marine Polyester

7-Year Limited Warranty

A lightweight 7.6 oz. solution-dyed marine polyester with a tight 600 × 600-denier weave and polyurethane finish. It balances water repellency, breathability, UV resistance, and easy handling for trailering, mooring, and storage.

Breathability Matters

Moisture can remain in carpeting, upholstery, bilges, and hulls after the boat is covered. A breathable marine fabric helps that moisture escape instead of trapping humid air beneath the cover.

Sunbrella® and Sun-DURA® are breathable marine fabrics, but fabric alone cannot provide all the ventilation a covered boat may need. Let wet surfaces dry before covering the boat whenever possible.

Vented support poles raise the cover for drainage while creating additional air circulation. They are especially useful for boats with carpeted or upholstered interiors.

Vented support pole allowing air to circulate under a boat cover

Ventilation helps reduce trapped moisture.

Support Extends Cover Life

Proper support helps rain and snow drain instead of collecting in low areas. Standing water adds substantial weight and can pull the cover into the boat, strain seams and attachment points, and shorten the useful life of either supported fabric.

Use a support designed to spread pressure across a broad cap rather than placing a narrow object beneath a tensioned cover. 1 or more vented support poles can create a drainage slope and add airflow; larger boats may require multiple poles.

Boat cover raised by 3 vented support poles for drainage

Understanding Fabric Weight

Marine fabric weight is commonly stated in ounces per square yard. The rating helps compare how heavy a cover will be to handle, but weight by itself does not determine durability, water repellency, breathability, or UV performance.

Consider the complete material specification, construction, finish, warranty, and intended use. Sunbrella® is the heavier acrylic option, while Sun-DURA® uses a lighter solution-dyed polyester construction.

Fabric Weight Comparison

Fabric	Weight
Sunbrella®	9.25 oz.
Sun-DURA®	7.6 oz.

Weight is measured per square yard.

Trailering Cover Recommendations

Best Fabrics for Trailering

Sunbrella® — premium acrylic with the longest limited warranty
Sun-DURA® — lightweight marine polyester with a 7-year limited warranty

Before towing, confirm that the specific cover, fit, and installation are approved for trailering. Fabric is only one part of a secure trailering system; a loose or poorly fitted cover can be damaged regardless of material.

When trailering, always secure your cover onto the trailer itself. The use of some sort of tie down strap is preferred because straps allow the cover to be cinched down and help prevent air from entering at the bow and ballooning the cover. Follow the cover maker’s attachment instructions and stop periodically to inspect the fit and straps.

Padding Protection for Trailering

Use non-abrasive padding on trailering covers to protect both the boat and the cover at every high-wear point. Inspect the padding regularly and replace it when it becomes compressed, loose, or worn.

Mooring and Storage Recommendations

Best Practices for Mooring

Let wet interiors dry before installing the cover
Properly support covers to prevent water accumulation
Keep vents open and check straps, support, and drainage regularly

Important: If you will be leaving the boat unattended for extended periods, supporting the cover is critical. Inspect the cover after storms so accumulated water or snow does not remain in low areas.

Best Fabrics for Mooring & Storage

Sunbrella® is the premium choice for long-term outdoor exposure, with solution-dyed acrylic construction and a 10-year limited warranty.

Sun-DURA® combines lightweight handling, water repellency, and a 7-year limited warranty for regular mooring and storage use.

Whichever fabric you choose, use the attachment method specified for the cover and maintain enough support and ventilation for the boat’s storage conditions.

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