kayak/canoe rack

[sandbar]

I have an 02 trail blazer with a factory/dealer installed luggage rack which I have used to carry canoe/kayaks on mostly short distances and relatively slow speeds. I saw a post by erayak about kayaks coming off luggage racks and was wondering just how big a chance I'm taking. I need to transport a kayak to the coast in a cpl. of weeks... long distance interstate speeds?? I could carry it in the back of the goat but it's a high milage gas drinking rolling crap shoot. Opinions on transporting with the factory roof rack would be appreciated.
When I do use the blazer to haul canoe/kayak I do secure them to the rack and run lines to the front and back bumper.