An improved windsurfing catamaran type vessel. The illustrated vessel has an improved steering mechanism that includes a relatively stiff but bendable plastic rod that is directly received within one or more guiding passageways or grooves formed in the plastic hull of the vessel. The plastic-to-plastic interface between rod and groove provides relatively low friction interengagement as the rod moves. The groove is open to ambient water, which will further reduce the friction. The rod has stiffness/flexibility characteristics that allow it to turn around relatively large radii while still being able to span relatively short distances without significant bending. A manual operative control member is pivotally mounted on the hull and connected to the rod in a manner which multiplies the force applied by the use; this provides the magnitude of force needed to move the rod with minimum exertion by the user. The presently preferred hull, which comprises a pair of side-by-side elongated hull sections is of the planing type by virtue of the generally flat lower surfaces of the hull sections. The illustrated hull is rotationally molded to provide internally hollow hull sections with a relatively thin outer wall or casing. The top and bottom walls of the hull sections are maintained spaced apart by a plurality of generally upright spacer sections which may be integrally formed during the molding operation. This type of hull skims or glides generally over the surface of the water as distinguished from displacement types which extend down below the surface. Generally flat bottom surfaces provide a maximized footprint for stability for the user while raising the sail and during windsurfing operation.