The Interislander ferry company says its Kaitaki vessel should resume sailing today, after it was held in dock last night due to a navigational fault.
A spokesperson said the problem was discovered during pre-departure checks.
The docking of sister ship Kairahi, which shares a berth with the embattled ferry, was also delayed and the ship is sailing behind schedule this morning.
Kaitaki stopped taking passengers and became freight only after the ship lost power off Wellington's South Coast in January.