A beacon has an associated post that is supported in relation to a watercraft. The beacon may comprise four major separable elongated members all mutually joined by an elastic cord extending along the longitudinal axis of the beacon. When separated, the four major separable members may fold in the compact configuration, thus enabling compact stowage. The beacon may comprise an internal light source, a flag or pennant, and reflective films to signal presence of the watercraft to others. The flag may be formed as a receptacle for receiving and storing the separable elongated members for stowage.