Pontoon cover

I just bought a new pontoon boat and am wondering if I should get a cover for it during the summer. I'm worried that the sun may harm the seats. If I should get one, is it better to get a cover for the whole boat, or just cover the individual seats? If I cover the entire boat with one cover, will there be a problem with mildew, particularly on the floor carpet?

Thanks

[yarcraft91]

If your boat sits outside, whatever you don't cover will be faded by the sun, soaked by rain and subject to dirt (think "birds"), leaves, bugs, etc.

I have a full cover for mine and I recommend that approach. There are air vents built into the cover and spacers to create an air gap under the "fencing", so enough air moves around under the cover that I've had zero mildew problems in 8 years. The seats still look like new and all I do is clean them with soap-and-water once or twice/season.