How to Cover Boats with Poly Tarps the Right Way

Introduction

Owning a boat comes with the responsibility of protecting it from harsh weather, UV rays, dirt, and moisture when it’s not in use. A boat is a valuable investment, and leaving it uncovered can lead to costly repairs over time. While shrink wrap and custom boat covers are common solutions, many boat owners turn to poly tarps as a practical and affordable alternative.

When installed correctly, poly tarps can provide reliable protection, whether your boat is stored outdoors during the off-season or simply parked for a few days. In this guide, we’ll explore the best practices for covering boats with poly tarps the right way.

1. Choose the Right Size and Thickness

The first step in covering your boat with a poly tarp is selecting the right tarp size. A tarp that’s too small won’t provide full coverage, while one that’s too large may create excess slack that can flap in the wind and cause damage. As a rule of thumb, measure your boat’s length, beam (width), and height, then choose a tarp slightly larger than these dimensions to ensure complete coverage.

When it comes to thickness, heavy-duty tarps with higher mil ratings (10 mils and above) are best for long-term boat storage. Thicker tarps are less prone to tearing, offer better UV resistance, and withstand heavy rain or snow more effectively. Light-duty tarps may be fine for short-term coverage but are not ideal for seasonal or year-round protection.

2. Prepare Your Boat Before Covering

Covering a dirty or damp boat can trap moisture underneath the tarp, leading to mildew, mold, and corrosion. Before installing the tarp, thoroughly clean and dry the boat’s surface. Remove debris, wipe down seats, and allow any standing water to drain. If possible, apply a protective wax coating on fiberglass surfaces to give your boat extra resistance against weathering.

It’s also a good idea to remove or secure any loose items inside the boat, such as life jackets, cushions, or electronics. These items can shift during storage and press against the tarp, creating weak spots. Proper preparation ensures that your tarp works as effectively as possible.

3. Support the Tarp with a Frame or Poles

One of the biggest mistakes boat owners make when covering with a poly tarp is letting the tarp sit directly on the boat. Without support, rainwater and snow can pool on the surface, putting stress on the tarp and eventually causing rips.

To prevent this, set up a support system. Many boaters use a ridge pole running the length of the boat, secured at the bow and stern, to create a peak. Alternatively, you can use adjustable poles, PVC pipe frames, or even makeshift wooden supports to elevate the tarp and allow water to run off. This “tent-like” structure extends the lifespan of your tarp and ensures your boat stays dry.

4. Secure the Tarp Properly

A tarp is only as good as the way it’s secured. Leaving it loosely tied down can cause it to flap in the wind, leading to tears and exposing parts of your boat. Always use the reinforced grommets along the tarp’s edges to tie it down tightly. Bungee cords, ratchet straps, or heavy-duty rope are effective options, as they provide flexibility while keeping the tarp snug.

For boats stored outdoors, it’s especially important to secure the tarp all the way around, not just at a few points. This prevents strong winds from lifting the tarp off completely. If your boat is on a trailer, anchor the tarp around the frame as well for added stability.

5. Regularly Inspect and Maintain the Cover

Even when properly installed, a poly tarp needs regular inspection. Over time, weather conditions can loosen straps, wear down grommets, or cause small tears. Make it a habit to check the tarp every couple of weeks, especially after storms or heavy winds. Look for pooling water, frayed edges, or areas where the tarp may be rubbing against sharp surfaces.

If you notice any damage, patch small holes with tarp repair tape or a tarp patch kit. For more serious wear, it’s better to replace the tarp altogether rather than risk leaving your boat exposed. A well-maintained tarp will extend your boat’s protection and save you from costly repairs.

Conclusion

Covering your boat with a poly tarp the right way comes down to preparation, support, and maintenance. Choosing the correct tarp size and thickness, cleaning your boat beforehand, setting up a sturdy support system, securing the tarp properly, and inspecting it regularly will ensure that your vessel remains safe from the elements.

While poly tarps offer a cost-effective alternative to custom covers or shrink wrapping, their effectiveness depends largely on the quality of the tarp you choose. It’s worth investing in heavy-duty tarps from reputable suppliers. Many reliable suppliers offer their products online, including through Amazon, where you can find heavy-duty, waterproof, and UV-resistant poly tarps suitable for boat protection. Checking customer reviews can also help you identify tarps that hold up well in real-world use.

With the right approach and the right tarp, you can keep your boat protected and ready for the next adventure, season after season.