The 34m catamaran has been slipped in Dunedin's upper harbour since mid-June for its two-yearly Maritime New Zealand survey, but has had numerous upgrades completed during that time, Southern Discoveries chief executive Tim Hunter said.
Winter was the low season for Milford Sound tourism, down by about a third, which was why the Pride of Milford could spend so long in Dunedin, he said.
Included in the upgrade was the overhaul of generators, work on the interior overall and kitchen, some equipment replacement, rewiring and recarpeting.
The Pride of Milford was 16 years old and the upgrade would make it ''an as-new vessel'' again, he said.
''Yes, there's about $200,000 gone into Dunedin's economy ... engineers, electricians and a lot of other contractors,'' Mr Hunter said.
The Pride of Milford is surveyed to carry up to 400 passengers and has five viewing decks.
She works alongside the 100-passenger, 21m-long monohull Lady Bowen, 240-passenger, 26m catamaran Spirit of Milford and 12-passenger, 15.5m monohull Milford Discovery, a charter vessel.
Mr Hunter said weather permitting, she would begin her return voyage to Milford Sound at the weekend.