A collapsible catamaran is described, comprising two hulls (1) and a frame (4) which connects the two hulls (1) in a detachable manner and carries plug-in noses (3) which engage in plug-in receptacles (2) of the hulls (1). In order to provide advantageous plug-in connections it is proposed that the plug-in noses (3) each comprise a guide tube (17) with at least one rubber-elastic clamping ring (18) which encloses the guide tube (17) on the outside, rests on an axial abutment (23) and can be subjected to axial pressure with the help of an actuator (22) penetrating the guide tube (17).