I've used a pair of the old 'rainbow racks' on a Vanagon without too much trouble. We replaced the bungees w/ cargo straps from a military plane and never had a problem w/ things falling off..

A better solution if you have the $$ are a set of Yakima or Thule racks. Not cheap, but bulletproof and can be used to carry other things as well. Keep in mind, however, that getting up there to tie down the boards can be a PITA.

Right now I store my longboards inside the van. At 10'4" it slides in through the back and the nose rests on a wooden bar suspended by the coat hook/knob things. A blanket over the back seat keeps the salt off. We usually leave the board out while drying off after a surf and most of the water goes away.

Let me know if you're ever in Viriginia Beach (or San Diego in a couple months) and we can go catch a few sets.

john