to the south as they approach the east coast of the North Island. Here warm water from the Tasman was not in evidence during 1949, suggesting that the East Australian Current turned back on itself and continued north in an anticlockwise direction to rejoin the parent current. The Hauraki Gulf lies between the February and August sea isotherms of 20.0 and 13.3–14.4° C. The average annual range therefore does not exceed 6.7° C. The following figures (from unpublished records at the Geophysical Observatory, Wellington) have been averaged from surface temperature data collected by coastal vessels between 36 and 37° S. Hauraki Gulf East of Coromandel Penin. °C. °C. January 20.6 20.6 February 20.0 20.6 March 20.0 20.0 April 19.4 18.9 May 18.3 17.8 June 17.2 16.7 July 15.0 15.6 August 15.0 15.6 September 15.0 15.0 October 16.1 17.2 November 17.2 17.2 December 19.2 19 2 These figures are considered to be fairly representative, but the margin of error must be considerable since when spot readings are made, no account is Text-fig. 6. Monthly average sea surface temperatures. 1935–1938 Auckland Harbour — — Coromandel Harbour…………