I bought a 5 X 8 flatbed utility trailer to haul my kayaks on. I built wooden bunks that allow me to carry the boats on edge, which I believe is the best possible way, since it puts the least amount of strain on the stiffest cross section of the boat.

A bonus is that I can use the trailer for a lot of other chores by just removing the bunks and installing sideboards. I did a lot of looking before I settled on an Iron Eagle trailer. It has a 3500 lb. capacity, so the work it can do is fairly unlimited.

All that said, I still haul my rec. kayak in my Tacoma's bed if that is the boat of the day. It sticks out quite a ways, but it's legal with a red flag.

The trailer can haul sea kayaks of any length. Mine is a seventeen footer, but I'm thinking about adding a nineteen footer one of these days.