Under which condition is a vessel allowed to operate without a valid registration?

Operating a vessel without a valid registration is permissible when the vessel is stored on land and not in use. The rationale behind this is that registration is primarily required when a boat is being operated on waters, either for recreational purposes or for navigation. When a vessel is on land and not being used, it is effectively out of the regulatory scope that enforces registration requirements. The other scenarios—repair, maintenance checks, and operation in non-navigable waters—typically involve some form of activity or presence on water, necessitating proper registration. Registration primarily serves as a means of identifying the vessel and ensuring compliance with safety and operational regulations while it is active on the water, which is not the case when it is stored or inactive.