I've transported my kayaks right side up, upside down, and in a J-cradle. It  depended on the vehicle, if the vehicle came with a rack, if I was moving 1 or 2 kayaks (or a canoe & kayak). With my current car & if I am just moving one kayak I transport upright using foam pads and straps going through the car doors. I always try some sort of bow & stern line also. I have used Thule racks but the ones I have do not fit my current car, and I have Yakima J-cradles because I got them on clearance. But they don't fit my current van so I have them attached to oak 1x2 inch cross-bars that I tie to the rack on the Van. 

What I am saying is I have no major preference but use what works at the time with what I have.

   Thanks, Ralph

  HikeAZ,

My wife & I transport two chesapeake kayaks on her car quite frequently. The crossbars are from Yakima (Thule crossbars would work just as well). The J-rack attachments are the stainless steel version from Packemracks.com The Packem racks are significantly less expensive than the name brand j-rack options. 

I secure the boats to the j-racks with 1" NRS tie-down cinch straps and use taglines front and rear. No problems at highway speeds(70-80mph), the boats hardly seem to move at all.

SignsEHT,

Thanks, a beautiful boat. It looks like you added a little padding between the J-rack and the boat. I will check out Packemracks.

Mike   

I transport the in cradles when ever possible.  My selected system is the Yakima system.  I've mounted racks on trucks, cars and the top of a pop-top camper.

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 One prefered system is the one on the truck. I carry the kayaks up right. I usually cover my cockpit with a cover. The wife's kayak covered "whomps" so we don't often put the cover on unless it looks like a big rain.  I use "hully rollys" on the rear to assist in loading the kayaks. The truck is a lot of places truck with suspension and tires to match.  I also carry a three step stool.  Note that if you get enough space between the bars, this one is 6 feet, you don't need the bow and stern tie downs.  Cars and vans often have racks more designed for short things. 

   [URL=http://s738.photobucket.com/user/GrumpyOldBakerman/media/biolumen%208%20-15_zps3jtlkv6y.jpg.html][IMG]http://i738.photobucket.com/albums/xx24/GrumpyOldBakerman/biolumen%208%20-15_zps3jtlkv6y.jpg[/IMG][/URL]

I have since moved the front rack foward over the cab to allow more support and less cantiliver on the kayaks when moved foward to give clearance for the trailer.

   Third time ought to do it....................This is the camp site at a biolumenscent paddle last summer.

I use the foam blocks from Malone (sold here) on rails.  I load by carrying the kayak on my shoulder as I go up a three step stool onto the tailgate.  The exception is that I use a set of Hulli Rollers on the aft rail when transporting our 79# Shearwater Double.  We take the cockpit covers off when driving.  It is amazing how little water will accumilate in the cockpit at highway speeds even in heavy rain.  Hereis a pict from yesterday before heading to John Pennekamp.  Today is Bahia Honda.

   Thanks, I have always used a J-rack but think I may try upright carry. I will start looking at options that will work for my RAV4.
 

Mike

As a precaution - make sure your cockpit cover is somehow secured so it will not blow off. Mine blew off my Wood Duck and I lost a foam seat but luckily the cover was tied to my deck rigging. (maybe I was speeding.)   

Canuck, a good tip. Utah has 80MPH highway speed limits (129KPH if you are north of the border:) so I suspect some type of tie-down for the cover would be in order.    

Mike

   Good point about the cover. Mine have a strap and clip foward to rigging plus a strap with buckle around the middle that goes all the way around the boat and over the cover.  The cover keeps things from blowing out and things from crawling/flying in. For some reason bugs like the inside of my cockpits.  Rain under way is minor. Rain sitting upright in the parking lot in the south can be impressive.

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I know a couple of kayakers that put covers on during lunch stops on a paddle to keep things out of the cockpit.