Put it where Thule tells you!
Posted by: nermal on Jun-21-12 9:18 AM (EST)
Engineers with expensive degrees and experience spent time determining where on your roof crossbars should be positioned. If you think you're smarter than them, then by all means, install your roof rack in a way that suits you, but do not be surprised if one day the rack fails.
If you are concerned about rack spacing, Thule has the excellent Slipstream cradle system which will offer plenty of support for long boats.