47 can rotate to better permit rotation of the support arms a conventional washer 64 may be positioned between the nut of the angle bolt and the outer surface of the support arms as best shown in fig7 a stop 65a in the form of a bolt extending through a hole in the support arm 47 is formed on the side of each support arm 47 to limit the outboard pivotal movement of the roller assemblies away from each other to facilitate drawing a boat on the trailer a crossbar member 66 is coupled to the upper end of each of the support arms 46 by any suitable technique such as by a pair of bolts 66a crossbar members 66 carry by suitable journals at their opposite ends hull engaging rollers 70 which are mounted for free rotation thereon and facilitate continuous engagement of the boat hull at all contact points to evenly distribute the weight during launching loading or transport through a multi planar and or compound pivotal action from the foregoing it should be apparent that the pivotally secured support arm 47 produces an arcuate motion of cross bar member 66 with rollers 70 about an axis formed along tube.