This interpretation clarifies regulations that apply to vessels operating in the guided sport (charter) fishery for halibut in International Pacific Halibut Commission Management Area 2C (Southeast Alaska) and Area 3A (Central Gulf of Alaska). Under regulations implementing the charter halibut limited access program, all vessel operators in Area 2C and Area 3A with charter vessel anglers on board catching and retaining halibut must have a valid charter halibut permit that was issued by NMFS on board the vessel. This interpretation clarifies that a valid charter halibut permit must be on board a vessel when the charter vessel guide on board is being compensated to provide assistance to persons catching and retaining halibut. A charter vessel guide is not required to have a charter halibut permit on board a vessel during a recreational halibut fishing trip on which he or she is not being compensated to provide assistance to persons catching and retaining halibut.