Abstract: Kayak comprising: a rigid base in several sections end to end joined to one another in a water-tight hinge-mounting so that they can be folded one on top of the other; a rigid keel in several sections spanning the hinge-mountings of the base sections and retained in brackets fixed to said base sections; two pneumatically inflatable sides joined at the base to the longitudinal edges of the rigid base; a covering canvas joined to the respective top longitudinal edges of the two inflatable sides and having at least one opening for a user; a seat located under this opening; and at least one rigid tensioning frame arranged to the rear of the opening and designed to brace the base, the inflatable sides and the covering canvas.