in fig1 of the drawings and is generally designated by the reference numeral 10 the marine vessel 10 is a conventional sailboat such as a hobie cat catamaran or sailboat which includes port and starboard hulls 11 12 front port and back port corner castings 13 14 respectively front starboard and rear starboard corner castings 15 16 respectively a port side bar 17 a starboard side bar 18 a rear or stern crossbar 19 and a black cross bar 20 the side bars 17 18 are conventionally connected between the respective castings 13 14 and 15 16 while the crossbars 19 20 are conventionally connected between the respective castings 14 16 and 13 15 thereby collectively defining a trampoline frame 25 within which is a trampoline 26 defined by two trampoline portions 27 28 a center gap or slot 30 between the trampoline portions 27 28 is spanned by conventional center lacing 31 and similar stern lacing 32 spans a stern gap or slot 33 between the trampoline portions 27 28 and the rear cross bar 19 a mast step 34 has secured thereto an end of a mast 35 which is stabilized by a plurality of shrouds 36 a rudder 37 38 is pivotally connected to the respective hulls 11 12 and the rudders 37 38 are simultaneously conventionally manipulated by movement imparted to a tiller 39 a sheet not shown associated with the mast 35 provides the requisite reaction surface for sailing under the influence of the wind but should the vessel become becalmed a conventional d c electric motor or trolling motor 40 fig1 through 5 can be utilized to provide propulsion in association with an electric direct current d c battery 45 through appropriate electrical conductors and alligator.