Boat covers come in as many shapes, sizes and designs as the boats they fit.  How do you know which cover is right for you?  You must first detemane what are you trying to protect your boat from, where your boat will be stored while not is use, and will your boat be trailered, moored or stored with the cover on?

What are you trying to protect your boat from?

If your boat has to sit outside and needs to be protected from the elements (sun, rain, wind, etc…) a cover constructed of good fabric is important.  The fabric must be water resistant, fade resistant, mold and mildew resistant.  It also should constructed in a way to vent trapped in moisture and to be fit well enough to stay on in windy situations. A pooling pole system will keep water from accumulating on you cover and then leaking through the fabric and filling up your boat.

 
If you are keeping it in the garage and need to keep the dust out, a cheap cover or bed sheet will do. But will you want your neighbors to see it, probably not.

Will your boat be trailered with the cover on?

A trailered cover should be fitted to your model.  A general fit cover will flap in the wind when you trailer it.  Flapping will cause wear to your cover and boat.  The cover will mar you gelcoat.  A cover should also be made of quality fabric so it doesn’t fade or the color doesn’t rub off or transfer on to your boat.  A trailerable vent system is designed to pull the air out of the cover to eliminate billowing. 

Will your boat be moored in the water or stored outside on a lift?

 The way that you store your boat, either on a lift or teathered in the water will affect the way your cover needs to be designed.  Your cover should be made of quality fade resistant, water resistant fabric.  Your boat will receive tons of sun and weather so your cover should be made to protect it.  A fitted cover with a pooling pole system will resistant pooling of water.  A strapless design will insure it stays on without the hassle of getting wet while trying to secure a strap.

Fabric

Sur Last Solution Dyed Polyester is the best fabric for your cover.  Its made here in the USA and held to very high standards.  The fabric is fade resistant, water resistant, and the color will not rub off or transfer its color.   The manufacturer of Sur Last® also makes Sunbrella®, also know in the marine industry for its superior fade resistant qualities.  Sur Last fabric is the choice fabric of OEM covers for Yamaha, Honda, Polaris, Mastercraft, Baja, Bennington, Malabu and other high end manufacturers.

Other fabric will not last as long and perform as well as Sur Last so take that in account when comparing price/life expectancy.

If you have any questions, please feel free to email me.  I have tons of experience with Personal Watercraft Cover and Marine Fabrics.   Terri at terripoppy@yahoo.com or http://www.poppycompany.com