A good PWC cover is absolutely essential to maintaining your pwc and hopefully extending the lifespan of your personal watercraft. Constant exposure to the elements, especially the sun, can cause your pwc to deteriorate. The sun can cause havoc with the rubber dash board and seats and can fade the colors of paint on the body.
The sun is made of fire so it is not surprising that it can causes burns and all sorts of other damage to your watercraft. Over time and when exposed to the sun rubber and vinyl can become less durable. The burning rays of the sun cause the vinyl and rubber bits to become more brittle. Once these materials become brittle and lose some of their strength then they are prone to microscopic tears. At first you might not even notice the breakdown in the material and the small tears but over time these tears get bigger and at some point cannot be reversed or fixed.
With the proper use of a pwc cover you can protect your machine from the harmful rays of the sun. Simply slip the cover on whenever you aren't using the machine. Another helpful hint is to try to store it in the shade. This might not always be possible but try to keep "shade" in mind whenever possible.
There might be times that you can't use a pwc cover and you can't park the machine in a shady spot. If you find yourself in this situation, make sure that you towel dry your machine, particularly the rubber dash and the pwc seat covers. The sun is harmful enough on the dry machine. Water droplets magnify the intensity of the suns rays causing even more damage to your pwc.
A seadoo pwc cover is also mandatory when transporting your watercraft. I don't mean that it is legally mandatory to use a pwc cover when transporting your craft. I'm only saying that it is VERY important to use a cover when transporting a pwc. I would hope the reasons for this are self-obvious. While on the high way or any road your uncovered pwc would be vulnerable to little rocks that are kicked up by your own car or other cars. My windshield has been cracked 4 times by little stones so imagine what a little rock could do to your paint job or even some of your dials. A pwc cover will not protect against anything but will provide adequate protection for the little stuff that gets kicked up on the highway.
Many competitive seadoo pwc racers insist on transporting their machines in completely enclosed trailers. Of course these machines are much more expensive than the average machine on the water. Furthermore these guys and gals make their livelihood with these machines so they are very protective when transporting their watercraft. The average rider will not have to go to the effort or expense of transporting their watercraft in an enclosed trailer.
A good pwc cover can come in many forms. Many people ask " can I use a tarp to cover my seadoo pwc"? The answer is yes. If you are simply a recreational rider and the pwc mainly stays at the cottage than you can simply use a tarp. There are two caveats in simply using a tarp. Unless your tarp is breathable, and I wouldn't think it would be, you will need to make sure that your machine is absolutely dry before storing it. Storing a wet pwc under a plastic tarp will cause moisture issues. The other caveat is that a tarp covered pwc must be stored in the shade.
Most people prefer to use a cover specially design for the make and model of their seadoo pwc. These covers are practical because they are breathable allowing moisture and heat to escape. These pwc covers also make for safe transporting of the machine on the highway. They also have a snug fit so if fastened properly there should not be any strap's blowing around in the wind while you are driving. Lose straps blowing wildly while you are driving are hazardous to those on the road including yourself but also can be very damaging to the watercraft.
You can buy fitted covers directly from the pwc manufacturer or from most marine supply stores. In the alternative you can commission custom covers with the name of the water craft stitched right into the cover. These custom cover makes a great birthday present.
Whatever you decide to do or whatever covers your decide to use will depend on your individual circumstances. Remember to think about the money you will save if you consistently use a good pwc cover.