A collapsible watercraft assembly can include a first pontoon half, a second pontoon half, and a frame member. Each pontoon half can have a top surface, a bottom surface, and at least one post. The first pontoon half and the second pontoon half can be positionable with respect to one another in an operating configuration and a stowed configuration. The operating configuration can be defined when the sterns of the pontoon halves confront one another and the stowed configuration can be defined when the top surfaces of the pontoon halves confront one another. The frame member can be concurrently engageable with the posts to fix the pontoon halves together in the operating configuration. The posts can be interconnected with one another when the first pontoon half and the second pontoon half are in the stowed configuration.