Make sure you keep your seats clean after use. Spray on a vinyl protectant to fight off UV rays. When not in use cover up your seats with a high-quality seat cover.

In my 2006 bass boat I use 100% silicone spray. they still look like new with no rips or thread coming loose, i spray them every other trip to the lake. learned it from a old man at the gas station one day while filling up. he had a 90s model pontoon that the seats looked like new and I asked him if he had replaced them and he said no, and then told me about the Silicone spray. it works. 

@pontoon-moose awesome insight. Which brand/type of Silicone spray do you recommend?

@ian-miller I just grab some at Wal-mart or Atwoods as long as it says 100% silicone I use it.