Donk said...
I have Thule Aero's on my Forester with a pod on one side and 2 boards on the other. I use SPT lockable tiedowns (4 metre length). The Pod can fit 2 x booms, 4 sails and a 400 mast plus accessories. See my avatar. Hope this helps.
Be very careful with lockable tie downs. I have some and after denting the rail of a board from the cable that runs through the tie down I only ever use them for overnight parking etc, never actually drive with the board held by them.