Vic,doesn't look like you have a roof rack.
When I carried my 12' Old Towne I attached it to
the roof rack with ratchet straps.
I did make some "channel stops" to fit over the
frame bars of the rack.
They acted to keep the canoe from moving side to side.
My system worked great.Traveled thousands of miles
with no issues even in cross winds.
Frank
Vic found photos of my setup.
You could add a bar front and rear
to hold the canoe.
The track down the middle is for the small wheel
on the front of the canoe.Keeps it from sliding off
the side when loading/unloading.
My 2 solar panels sit on each side on the rear section of the rack.
Frank, thanks for that. Actually, there is a roof rack up there. Super low profile, 1" square alum bars attached to the T-slot tracks. I have 4 T-slots running the length of the roof, so the 1" bars are on there pretty sturdily!
Curious about your shaped gunwale cradles. How did you make those? I think my canoe will be resting almost on the alum roof rack, with the exception of some left over 1/4" vinyl flooring glued to the racks to keep the alum/alum contact to a minimum.
I was also thinking of having some L-channel at the front that would limit/guide forward travel of the canoe.
Regarding ratchet straps, I have heard that these are not advisable for canoes, as you can put TOO much pressure on the hull. That said, I have used them before!
It looks like I can use ratchet straps from the roof racks to the carrying handles at each end of the canoe... those are sturdy and would also limit front/back travel at each end.
Stay tuned, and keep the ideas coming!