I just bought a Wenonah Adirondack canoe and i am putting a rowing rig into it. The only way i can transport the whole thing is with the canoe up on the roof rack facing upwards with the rowing rig facing up. Now, I know that canoes are best supported on a roof rack on their gunwhales but what options do i have? should i use a kayak saddle to better support the canoe? I do not have enough room to carry the rowing rig separately inside the vehicle.
Okay, but be mindful of rainstorms
A canoe having the approximate dimensions of the Adirondack will gain roughly 100 pounds for every inch of water that pools in the bottom of the boat (this is based on the relationship of waterline displacement to payload for a boat of this size and shape, because the relationship of weight to "waterline" is the same in either case, ignoring the relatively insignificant weight of the canoe). I don't know where you live, but in my neck of the woods, an upright boat can end up with three inches of water in the bottom in a pretty short time during a downpour. When thinking about that weight-to-waterline relationship and how much water might pool in the boat, remember that since the open top of the boat is quite a bit larger than the area where the water pools in the bottom, the depth of water in the boat will significantly exceed the actual rainfall amount. You won't want to leave this setup unattended on your car roof with storms in the forecast, and a trip home in a downpour may require periodic stops along the way to bail the thing out. It won't happen often, but it will be pretty inconvenient when it does.
Build your racks up with the addition of 2x4’s secured to the existing crossbars? This may give you enough distance to clear the oarlocks.