John,

Despite a few horror stories of people losing the kayaks off their cars at highway speed, I wouldn't worry too much. I have a bit more reason than most to worry about it since I have to cross the 5-mile-long Mackinac bridge. I once had to creep across the bridge at 25mph into a 50+mph wind off of one corner of the car. I thought I'd loose the kayak for sure on that trip. The kayak rotated a good foot at the bow before the bow line really kept it from going farther.

Semi's can cause a bit of a jolt when wind conditions are just right, but it's not bad. You're better off than most in terms of stability -- most of us with cars have maybe 3 feet between load bars, and you have more like 6, so your boat will be anchored more toward the ends and will be more stable. I haven't noticed any lift, and I doubt that your wooden rack will lift out. It would have to lift straight up, and it would probably be more likely to lift in the front, which would cause the legs to bind up in their holes anyway.

Dean

> 1) What is the most significant concern at highway speeds, with crosswinds
> while on long bridges with semi's - lift, or lateral movement of the kayak
> across the roof, or rotation of the kayak in a horizontal plane?

> 2) Does the shape of the kayak provide lift, or is it neutral? I remember
> a talk about the AWACS and the radar dome on the plane supposedly provides
> 10 degrees of lift ... I can imagine my kayak lifting out of the pick-up,
> rack and all!

> I've already blown my budget on the kayak building supplies, wetsuit,
> paddle, etc. and haven't even got the foot rails, PFD, etc. yet. Do I need
> to be concerned about a rack, too?