The Tasmanian Harbour Authorities' (THA) membership comprised the State's Harbour Authorities, Boards and Trusts. It acted as the peak body for matters of common interest to its members. After 1924 the name was changed from the 'Tasmanian Marine Boards' to the THA. Up until 1952 the THA was chiefly a periodical conference of Harbour Authorities. In the February conference of that year it was resolved to form a standing committee to deal with urgent matters of mutual interest that arose between conferences. At the 1964 conference it was resolved to form a properly constituted Association which was duly formed in September of the following year.