(1) Tax paid beer may be sold direct by beer distributors to:
(a) Vessels engaged in foreign commerce and operating on regular schedules.
(b) Vessels engaged in interstate commerce and operating on regular schedules.
(c) Vessels commonly known as "tramps," engaged in interstate and/or foreign commerce but not operating on regular schedules and taking cargo when and where it offers and to any port.
(2) Beer may not be sold direct by beer distributors to any other class of boat or vessel unless the boat or vessel is in possession of a proper retail license.