I put my 70lb Kayak on the roof rack the first time I took it out. Later that night I returned the roof rack and purchased a utility trailer.
I love the utility trailer. I can fit 4 kayaks easily. I pickup my own mulch, stones, etc. Saved me a lot on delivery cost.
I purchased this except mine is 6x10.
http://www.tptrailersinc.com/store/OPEN-LANDSCAPE-TRAILER--UTILITY-TRAILER-PREMIER-MODEL-LE-5-X-8-w-24-MESH-SIDES--GVW-2995-OSCARItem_2=TP1805.aspx
Bryan