Cradle. Get one. Then guy the cradle with tensioned cable and/or industrial strength webbing to the trailer. This is a pro job and they earn their money by avoiding the 101 ways this can go wrong (like your boat breaking into two pieces that land on two SUVs, one filled with nuns, the other with orphans.
Want to see how idiots can pooch a trailer job? Ask me. The legal crap surrounding this clusterscrew started in May and is only now concluding to my satisfaction.
