UV ray concerns

I'm wondering what concerns members have about UV ray damage (or UVB).  When I load my yak on the lumber rack in May & move to the Donner lake area it stays in the elements until late September..  It's either in the h2o or on my truck..  No garage & it's a lot easier to leave it on the rack..  What troubles am I in for if I don't cover it when ever possible?

The plastic will fade then get chalky and brittle, if you are concerned cover it.

Shimmy is right John, you'd better cover it, especially at higher altitude where UV is stronger. One thing you can do that I do to all my boats is coat them with a UV spray protectant called 303. It's space age stuff, basically sunscreen for your kayak. You only need to apply it every three months. It can be sprayed on all your gear as well. spray it on and then wipe it off a few minutes later after it's done it's chemical reaction thing with the pores in the plastic polyethelyne. Good luck.

Thanks for the comments..  Where can I purchase "303" spray protectant around the Napa or Truckee areas?

If anybody has ziplock-style dry bags, that 303 stuff works great on them. When they get old or dried out, the ziplock is really hard to close, but after a 303 treatment, they work just fine.

Sample kit for $5.00  http://www.303products.com/tech/index.cfm?fuseaction=category.display&category_ID=113&CFID=10505621&CFTOKEN=57344351