About 700 passengers had their trips across the Cook Strait delayed today after a fault on the Interislander's Kaitaki put back sailings more than three hours.
A mechanical fault on the Kaitaki meant the bow door was not closing properly and today's 8.30am sailing was delayed until 12.40pm.
The Kaitaki's scheduled sailing from Picton at 1.15pm today was delayed until 4.40pm.
KiwiRail said the problem was the inner and outer bow door were not sealing properly.
It follows a problem with the same door last year, but that problem was pins not locking into to place.
KiwiRail's group manager of operations Ian Hill said it was frustrating to have more problems with its ferries.
"We would like to apologise for the disruptions we have caused. We are very disappointed at this stage because we've had such a good summer."
"We've made 100 percent of our scheduled sailings over that time," Mr Hill said.
He said if the crew had any safety concerns, ferries did not leave port.
"It's disappointing for the crew because they work immensely hard to maintain them to a high standard."
"It's not like a car where you can just stop, hop out and walk. It's bit like an aircraft, if it's not safe, we don't sail."
He said Interislander staff were at both the Wellington and Picton terminals this morning to keep passengers in the loop.
"We got some good feedback from the passengers on what we could do better."
"It sounds like communication is one of those things we could step up a little bit more."
"It got to the stage where we just weren't updating passenger on as a regular basis as we should have," he said.
KiwiRail said the ferry would be back to usual timetable tomorrow morning.