Engine problems have forced Port Otago's new $11 million tug Taiaroa, on its maiden voyage to Port Chalmers, to divert to Lyttelton's dry dock.
The 24.5m, 250-tonne tug, built by Netherlands company Damen in Da Nang, Vietnam, is on a course between Brisbane and Cook Strait and is expected to reach Lyttelton by Sunday, Port Otago chief executive Geoff Plunket said.
He said the four-man specialist delivery crew had reported a leak, stemming from a problem with the engine cooling system.
While it was ''not significant enough'' to consider putting into an Australian port, Lyttelton had a berth available in its dry dock facility, Mr Plunket said.
''We don't believe it to be significant. It could well be just a [blown] seal.''
Taiaroa, which is still under warranty with Damen, would arrive in Lyttelton on Sunday and go into dry dock on Monday. The voyage is more than 5000 nautical miles (9300km).
Mr Plunket had expected it to arrive in Dunedin on Monday, but it was ''more likely'' to be sometime between July 18 and 20, he said.
