I carry all sorts of boats on the roof of my van with nothing but Styrofoam
and stout line... the heaviest of which is a Dyer dink... a 10 foot lap
strake wooden sailing dinghy.. complete with oars, mast and boom ... I keep
the sails in the bus...with the dog... if you rig your boat snuggly on the
Styrofoam it goes no where... I have carried such a beast and others up top
for a couple of thousand miles with no ill effects... with an outboard in
the luggage rack at the same time on occasion