As I get close to finishing my kayak, my thoughts turn to how I will transport it. It was easy with the canoe I built where I used a T-bar and a single cross roof rack. The curve of the kayak precludes that plan. In addition, my plan is to build another kayak for my wife which means I will need to transport the kayaks on their side with a “J” stye cradle, so I might as well do that now for my Guillmont. Looking at the many posts here it does seem that tranporting the kayak on it’s side will subject it to a lot more wind, but as long as I use lines from the bow and stern (possibly two lines from the bow in a triangle arrangement) attached to a hood anchor, I should be fine. My question is first is this all correct, and next is there a better “J” style cradle I can purchase or are they all about the same?
Welcome to the most harrowing aspect of boat ownership- driving at highway speeds with Your Precious strapped to the roof. It is easy to overthink. see the picture below - I think that’s a 24 footer. It’s doable.
They didn’t have the bow and stern lines set yet.
My preference is to carry a boat either keel or deck down. That provides to most surface area for the supports. Boats have lift, so keel down tends to lift the boat against the straps, deck down pushes it into the supports. On its side is a little more complex. But in the end, your boat is pretty strong - it’s unlikely that aerodynamic forces will damage the boat.
I look for:
Spacing - the farther apart the supports (along the length of the boat) the better. This is typically a vehicle imposed limitation.
Supported surface area - the larger the boat surface supported, the less you concentrate stress. Firm foam pads are great
Bow and stern lines are a MUST, but they aren’t there to hold the boat down. They’re not slack, but shouldn’t be taut. They can induce a large bending moment on the hull, well away from the mounts, which can snap a boat. They are there to limit side to side (yaw) movement, and most of all, to keep the boat from shooting forward hinder hard braking. The largest dynamic force your boat will see on the road is a hard stop. I’ve seen the aftermath of boats that squirmed out from their hold downs outer hard braking, and without bow lines, became a harpoon.
In the picture above, they have nice, adjustable pads. I usually use thick, firm pads for my long boats which conform to the hull pretty well. I haven’t had to do it yet, but I could see doing a little foam carving if necessary. But you’re going to have to work with the limitations of your vehicle in terms of bar spacing and overall width
I’ve always added redundant safety lines - no single point of failure if one comes loose and always remember, don’t overtighten:
Would you recommend a four piece kayak saddle arrangement compared to something like the Malone seawing?
I think I am going to have to look at two solutions, what I do now with one kayak and what I will do with two when the wife wants to join me. When just myself, I like the idea of rear loading which puts me in a saddle design. With two kayaks I don’t think two saddle systems will work since the Prius roof is only four feet wide. Is it possible to have one kayak supported with a saddle and the other with a “j” design?
I like the thule that have sliders in the back and saddles in the front. very easy to slide them up from the back, very secure. little windage.
and yes, straps for bow and stern for any highway work. pictures of a night heron 18 ft and a shearwater 17
i don’t like the side saddles due to the extra windage from the side.
do pay attention to weight and your cars bar weight limits…the strippers are often quite light and not a problen…but some folks don’t read the manual which sometimes have surprisingly low limits…and overload.
h
I have been using Thule folding J cradles for decades with no issues and occasionally have squeezed a 3rd boat in the middle with foam blocks.
I have been known to not follow the dimensions for crossbar spacing as I like to have then fore and aft of the coaming. The other thing I do is make sure the front cradles are closer together than the rear. I see too many cars on the road with kayaks splayed apart in the front causing too much wind resistance
I now have a taller ride and am thinking of buying elevator shoes 
Dan,
Thaks for the informative pictures! So far as the elevator shoes. Check these out. I just ordered them. Might help me access the tough to reach areas! EasyRoof AccessMaster Car Door Step for Roof Rack | Ancestral Outdoors
I was joking of course. I did buy a step thing similar to your link and find it very helpful.