Can you get a kayak on the factory roof bars?

[rallysport]

I recently purchased the factory roof rack and bought a Yakima Frontloader bike rack (The combo works great by the way).
I was curious if it's safe and possible to get a kayak up on our 1 series?
My uncle brought over is Thule Hull a Port kayak carrier (J style carrier) and it looks like it doesn't sit too well on the factory bars. I searched Thules web site and it does say it works on most factory bars so I was wondering if anyone has experience getting a kayak up there?
Any help would be greatly appreciated