The Maritime Union says after a run of serious events with Cook Strait ferries it is "really concerned" about the safety of workers and passengers.
The Bluebridge ferry Connemara arrived back in Wellington this morning, about five-and-a-half hours after it lost power and started drifting in Cook Strait.
This was the latest in a string of disruptions, delays and issues with Cook Strait ferries, including the Aratere running aground in the Marlborough Sounds in June with 47 people on board.
Maritime Union national secretary Carl Findlay told Nine to Noon it was lucky the Connemara was not grounded overnight on Thursday.
"It was only by luck that the wind was blowing in the direction that didn't push it into land."
The recent woes afflicting Cook Strait ferries pointed to escalating issues on the health and safety pyramid, at the top of which was death, he said.
"I'm really concerned that this is where this is heading."
The union had been raising health and safety concerns about the ageing ferry fleet for some time, but these had been ignored, and anxiety levels among workers were "going through the roof", he said.
"I don't know what it's going to take for the government to get it, but the anxiety levels amongst all of our members with these vessels and the issues they're having is ... going through the roof.
"There's some real issues there that need to be dealt with and they just seem to be ignoring everything we're asking and not coming up with any answers."
Although all the passengers had disembarked, and no one was injured, they were having problems getting the rank down, so "all the trucks, vans and cars were still on board", he said.
Nine to Noon host Kathryn Ryan pointed to recent changes to ferry routes across the Cook Strait, which would buy time if they lost power and drifted.
This had merely added an hour to the sailing time, and did not solve the problem of the ageing vessels, Findlay said.
"We're still not getting any answers and for the life of me I can't see why they can't understand why they don't see it as a priority, given all the history of what they know is happening with these vessels.
"I mean, honest to God - what are they waiting for?"
Grounding unlikely - marine expert
Meanwhile, a marine consultant said it was unlikely the Connemara ferry was in grave danger when it broke down last night.
Marico Marine senior partner John Riding said the ship was well within range of Wellington's ship monitoring system and drifting slowly towards the centre of Cook Strait in calm weather.
"The most difficult part of this route is Tory Channel entrance, where the currents are much stronger. And a breakdown there becomes more difficult to resolve, because [for] tugs to come from Wellington takes longer."
It was not uncommon for fishing boats or other vessels to safely drift in the Cook Strait as they await course instructions, and tugs would only have been called when it became obvious the fault could not be addressed at sea.
Tugs up to the taks - CentrePort
CentrePort's tugs - which are not designed for open sea rescue - towed the vessel to safety.
The Wellington port's chief executive Anthony Delaney said the weather was favourable, but even if it had not, the tugs would still have been up to the task.
"Our people are trained to respond to these types of events, they're capable people. The equipment and the tugs in different weather conditions are likely to have been able to hold it, then you've got the ship's anchors and the like as well."
New ferries cancelled
The Inter-Island Resilient Connection (iRex) project was cancelled late last year after the government denied KiwiRail's request for further funding.
The project had been set to deliver two rail-enabled Cook Strait ferries by 2026.
Minister of Finance Nicola Willis warned at the time of a cost blowout, saying the cost had gone "many times" beyond what was originally scoped by the previous government.
There has been no decision since then on alternative options.
Earlier, Simeon Brown told Morning Report that in this year's Budget, Maritime New Zealand had been asked to undertake a business case for an open-water tug service to assist in such circumstances.
This was a "nice to have", not a priority, and tugs could not have completed a full salvage operation anyway, Findlay said.
"They need to fix the problem [of ageing ferries] first and foremost, and then worry about the contingencies a bit later, but they can't even do that.
Labour's transport spokesperson Tangi Utikere said the Cook Strait ferries were a "ticking time bomb" for maritime disaster.
"We've seen disruption, we've seen delay. Disaster is a ticking time bomb that will be next if the government does not do anything in terms of identifying what their replacement ferry options are. We've been waiting, waiting, waiting."
The coalition was not moving quick enough on its solution for the crossing, having scrapped Labour's plan for rail-enabled ferries at the end of last year.
"The concerns that have been raised by the Maritime Union around health and safety are real and when you get an ageing fleet that's naturally what's going to happen, particularly with the government who have pushed out the current Interislander fleet for at least another five years."