An inflatable watercraft of the kayak type including a hull including: a longitudinal bottom comprising a central longitudinal edge and two lateral longitudinal sides, so as to have a V-shaped cross section, the bottom comprising at least one inflatable shell, and a stiffening upper structure comprising two lateral longitudinal inflatable shells and at least one transverse element mounted between the two lateral inflatable shells, each lateral inflatable shell being mounted on one of the lateral longitudinal sides of the longitudinal bottom, in which each of the two lateral inflatable shells comprises two superimposed walls, each of said walls including a textile mat and being connected together by a multitude of connecting threads distributed over the entire surface of said mats while forming a structure suited to be inflated to a pressure capable of stiffening said structure.