Why Floating Covers Blow Away — and How Ballast Fixes It

Floating covers earn their keep by being light and easy to deploy. But that same lightness is their weakness on exposed sites: wind.

The physics of wind uplift

Wind moving across a water surface exerts both drag and lift on anything floating there. For a light cover element, the aerodynamic forces can exceed its weight, so the wind:

• Lifts individual elements off the surface, and
• Pushes and piles them toward the downwind shore, opening gaps and exposing the water again.

The lighter the cover and the more exposed the site, the worse this gets. A cover that performs well on a sheltered pond can underperform on a windswept reservoir.

The fix is mass — sealed in at the factory

The straightforward way to resist wind is to make each element heavier. The clean way is to add that weight as water ballast sealed inside the ball — cheap, inert mass with nothing to install.

That is what Armor Ball® AQUA does. Each ball comes pre-filled with sealed water ballast, so it weighs roughly 275 g versus about 50 g for the shell alone. The heavier balls resist uplift and displacement, raising the cover’s wind rating from the standard 35 MPH to 75 MPH (120 km/h) — and they do it with:

• No pumps
• No anchors or cables
• No liner penetration

There is nothing extra to engineer into the basin and nothing mechanical to maintain. Because the ballast is sealed inside each ball at the factory, it never mixes with the liquid you’re covering and can’t drain away — unlike field-filled “self-ballasting” designs, whose open chambers can harbor algae and sediment and lose ballast back into the water body.

Choosing the right wind rating

• Sheltered to moderately exposed sites: standard Armor Ball® (35 MPH) is the lowest-cost, easiest-to-deploy option.
• More exposed sites: Armor Ball® AQUA (75 MPH).
• High-exposure or maximum-coverage sites: AWTT’s range extends to 130+ MPH with covers such as Hexprotect® AQUA / Rhombo Hexoshield®.

Not sure where your site falls? Request a wind assessment and we’ll recommend a cover.

Learn more: Armor Ball® AQUA · How it works · Floating cover types compared