kayak trailer. bunks or crossbars?

what do you think is more beneficial with respect to the health of the kayak hull?  driving with a kayak on bunks, or on crossbars? 

I am leaning towards crossbars.  I think for long distances, I would flip my Hobie Outback upside down on crossbars and strap it down.  no rain issues, etc.  and the Hobie Manual does state that storing it upside down is the best way.

thoughts?

Upside down is always the best. Right side up is just for convenience and will slowly deform on certain hull. Some faster than other.

I always transport my Outback and Oasis upside down on the Thule Hullavator and store them upside down in my garage.

Paul

Bunks made from pvc pipe is the best option, IMHO.

Bunks are more convenient for rigging and prep possibilities, but upside down is better for hull longevity and integrity. My $.02

Flat bed? You can store a kayak flat, upright on the ground, so why not carry it on a trailer the same way?

Bunks are more convenient for rigging and prep possibilities, but upside down is better for hull longevity and integrity. My $.02

Hobie Islands (both AIs and TIs) are heavy boats, and I've never heard of anybody transporting one upside down on a trailer, and I've cannot recall hearing of one that was properly supported (Hobie cradles or PVC bunks) having problems. I don't know why the same would not hold true for other Hobie kayaks.

If you are worried about warranty issues, get the Hobie cradles. However, IMHO, pvc bunks are superior in every way (better support, cheaper, easier to slide the kayak on and off).