the invention is a trailer designed for use with catamarans and perhaps other multi - hull vessels which are intended to be trailed on the highway but have a beam when sailing much broader than the permissible widths of vehicles allowed on the highway , so that the hulls are separate and can be collapsed together for trailing , and expanded to the proper width and assembled with frame support members when ready to sail . the trailer is designed to carry this type of vessel and has a pair of elongated cradles mounted on the ends of outrigger beams which are swung outwardly to put the hulls at the proper spacing for attachment for sailing , with the outrigger beams being swung inwardly by a central traveling beam to which they are pivoted to draw the cradles together side by side in transport - ready position on the trailer .