There are five classes of membership of the Institute:

Honorary Members who shall be distinguished persons with existing or previous navigational interests, or members who have rendered outstanding service to the Institute, and upon whom Council sees fit to confer an honorary distinction.

Fellows who shall be members who have attained a high standard of technical eminence in the science of Navigation, or who have rendered outstanding service to the Institute.

Members shall be persons who have an interest in the advance of the science of Navigation and are approved by Council.

Student Members shall be persons who are studying at a recognised University, College or School, preparatory to entering a career as a navigator or other responsible position closely allied to the science of Navigation and Position Finding.

Corporate Members shall be Universities, Colleges, Manufacturers, Operating Companies or other organisations involved or interested in the science of Navigation.