Our most popular model, the UltraLift-2 polyethylene tanks- designed and manufactured by HydroHoist - are highly resistant to impact or low-water damage. Flexing when stressed, the tanks then return unharmed to their original shape! All the steel parts are above the water*- a completely new concept in the boat lifting industry- to defy rust, corrosion, and the elements. And protecting your boat for years of convenient and care-free storage.