October 1905 saw the commencment of a daily service year round utilising Rotomahana (1,727grt/1879) and Pateena (1,212grt/1883).
The latter ship was replaced later the same month by the Mararoa (2,466grt/1885).
New Zealand's pre-eminent shipping company, the Union Steam Ship Company of New Zealand Ltd., was formed in Dunedin in 1875 by James Mills and a group of Dunedin merchants.
Operations commenced in July of that year and the company quickly expanded with services on the New Zealand coast, to Australia, the Pacific Islands and across the Pacific to North America.
Initially she ran in partnership with Rotomahana until she was replaced in 1908 by Mararoa.
Early in her service, Maori broke the record between Lyttelton and Wellington, making the passage from wharf to wharf in 8 hours, 23 minutes at an average speed of 20.8 knots on 27 December 1907.
Maori made her last voyage in the service on 5 January 1944 and was laid up in Wellington. Company was able to secure the first licence issued under U. war regulations for the building of a passenger vessel.Tamahine, dating from 1925 and of 1,989grt had become too small for the traffic offering and this arrangement continued until the entry into service of Rail Ferry Aramoana in 1962.In 1964, the decision was taken to convert Maori into a drive-on/drive-off configuration following the success of Aramoana on the Wellington - Picton service. This had the effect of reducing her gross tonnage to 7,298 and her passenger capacity to 790, but with space available for 100 cars.From 1920 until 1931, the service was maintained by Maori and Wahine with Mararoa acting as relief ship.Rangatira, a new turbo-electric vessel of 6,152grt built by Vickers Armstrong, Barrow-on-Furness, was launched on 16 April 1931 and sailed for New Zealand via Panama on 8 September 1931.