Mary-
I set my trailer up to support my boat by the beams since Jim Boyer and Greg Goodall both told me I "must" do this and sent photos of their recommend trailer setup. According to Jim the worst "working" (he called it "racking") the beams/hulls go through is when the hulls are strapped down tight to trailer crossarms (regardless of whether you use rollers/cradles/etc.) since the trailer will flex while under way and this will "work" the beam/hull connection much worse. Jim also espoused a heavy steel trailer to both decrease trailer flex as well as improve the ride- he said the light aluminum trailers were bad for cats. This is the reason I support my boat at both corners of the front beam but at the middle of the rear beam- that way if the trailer "twists" there is no induced twist on my beams/hulls <img src="http://www.catsailor.com/forums/images/graemlins/blush.gif" alt="" />. I think the critical difference here is we are used to thinking of hulls that weigh a lot (ie Hobie 16 or 18 hulls for instance) vs the very light F16/ "A" cat hulls. If you want to see how much a trailer flexes under way just follow an empty cat trailer for a few miles OR put some upright tubes bolted to the end of your crossarms and watch them in your mirror as you drive- they are all over the place! Strapping a (preferably heavy) boat down actually dampens this movement because the flexion is transferred to the boat! <img src="http://www.catsailor.com/forums/images/graemlins/shocked.gif" alt="" />

Kirt