Assuming that a general process of dominance ranking has taken place through the improvement of internal accessibility, a simple model depicting the evolution of the spatial patterns of New Zealand port locations is developed to provide a standard for gauging changes in the status of seaports. By applying the idealized-type sequence to the distribution of New Zealand ports at different times it is shown that Auckland, Wellington, Lyttelton, and Dunedin have grown faster than the other ports. The full realization of the process of dominance ranking with the concentration of activities on a single port, however, has been hindered by local vested interests, the perishable nature of some of the commodities handled, and the interference of the central government.TUDIES of seaports have varied widely in S their emphasis ranging from a concern with changes in physical layout, through detailed examinations of the character of shipping handled, to cargo hinterlands and forelands1 Yet, with the exception of recent work by Taaffe, Morrill, and Gould,2 little attention has been focused either on the evolution of the spatial patterns of port locations with the improvement in internal accessibility or on the accompanying process of dominance-ranking. Even in the latter study the development of seaports was not pursued to its logical conclusion, as it was only of secondary importance to the expansion of the transport network in underdeveloped countries as such. Indeed, in their preoccupation with the development of landward communications they neglected changes in the organization of maritime space, which is as essential to the development of a port as land transport.In an attempt to incorporate both the changes in the maritime and land transportation networks a simple model is developed to serve as a yardstick for comparing changes in the evolution of seaports. The validity of the model is tested by applying it to the distribution of New Zealand seaports at six different dates between 1853 and 1960. Unfortunately there is a paucity of suitable yardsticks for gauging a port's status over this period of time. Indeed, the only measurement available is thc value of overseas trade. As a result the choice of the initial and terminal years of this study stems from the fact that 1853 is the first year when statistics of the value of overseas trade for the whole of New Zealand are available, and 1980 is the most recent year for which statistics are published. Although the value of overseas trade provides a useful criterion for gauging the status of a port, the fluctuating worth of the pound sterling is a serious drawback to its use over a long period of time. In this study all the values are, therefore, expressed in terms of the pound sterling in 1911.3 However, the resulting adjusted values can only be taken as a crude guide to the changing status of seaports, so The crude index for conversion to 1911 values (1911 = 100) were 1853 = 175, 1865 = 175, 1881 z 125, 1938 = 80 and 1960 =