The invention relates to a water vehicle comprising a solid hull and a solid outer edge wall (5) above the waterline, and a recess (9) extending on a substantially horizontal plane wherein an elastically deformable safety element (11) is firmly arranged and is folded in a first operational state and is inflated in a second operational state by means of compressed gas from a compressed gas source (21). The invention is characterized in that at least one undercut projection (15) is formed in the recess on the outer edge wall and in that the safety element in a negative form with respect to the projection consists of at least one recess (11.1, 11.2), whereby the projection engages in a positive and non-positive fit into the recess.