Ditto Zuhl. Fresh water is ok to sink the trailer, but better not try it in salt water too often.

I've always used front cradles and rear rollers (for easier off loading on a ramp in fresh water). I do add extra cushioning on the rear rollers when trailering out of the club grounds. Seems as if most of the weight is on the main beam (i.e. front cradles) when stored with the mast up.