In selecting straps, a lot of folks believe that they need straps strong enough to hold their boat to the trailer. But in reality, they need straps that are strong enough to hold the trailer to the boat. If I were in the strap market, I'd figure out what my trailer weighed, put a factor of safety of 5-10 on each strap and buy what works for you from a convenience standpoint. And then when the straps aren't in use, I'd store them out of the weather and sunlight for a long life.