Since the 1969 election, the number of electorates in the South Island was fixed at 25, with continued faster population growth in the North Island leading to an increase in the number of general electorates. There were 84 electorates for the 1969 election, and the 1972 electoral redistribution saw three additional general seats created for the North Island, bringing the total number of electorates to 87. Together with increased urbanisation in Christchurch and Nelson, the changes proved very disruptive to existing electorates. In the South Island, three electorates were abolished, and three electorates were newly created (including Tasman). In the North Island, five electorates were abolished, two electorates were recreated, and six electorates were newly created. The Tasman and West Coast electorates replaced the former Buller and Westland electorates in 1972.
Population centres of the original Tasman electorate were Collingwood, Takaka, Motueka, Richmond, Havelock, Picton, Owen River, Murchison, Saint Arnaud, and Springs Junction. In the 1977 electoral redistribution, the city of Nelson had experienced population growth and many of the Nelson suburbs were transferred from the Nelson electorate to the Tasman electorate. To compensate for this, Springs Junction went to the West Coast electorate, and Picton was transferred to the Marlborough electorate. There were only minor boundary changes through the 1983 electoral redistribution. In the 1987 electoral redistribution, the remaining area of the Marlborough Sounds including Havelock transferred to the Marlborough electorate.
McRobie, Alan (1989). Electoral Atlas of New Zealand. Wellington: GP Books. ISBN0-477-01384-8.
Norton, Clifford (1988). New Zealand Parliamentary Election Results 1946–1987: Occasional Publications No 1, Department of Political Science. Wellington: Victoria University of Wellington. ISBN0-475-11200-8.
Wilson, James Oakley (1985) [First ed. published 1913]. New Zealand Parliamentary Record, 1840–1984 (4th ed.). Wellington: V.R. Ward, Govt. Printer. p. 266. OCLC154283103.