AINA’s members drawn from the public, private and third sectors.  They include the Canal & River Trust, the Environment Agency and the Broads Authority in addition to, local government authorities, private canal companies, internal drainage boards and a variety of public and charitable trusts.

Most AINA members are defined as navigation authorities by their own Acts of Parliament (some of them more than 250 years old) which regulate the operation of their waterways.  Others, such as some local government authorities, have inherited the status of navigation authority through various statutes.  Between them, AINA members have responsibility for over 5,500 km of navigable, inland waterways which include canals, river navigations and lakes.