The government is being challenged on the reasons for putting two navy inshore patrol vessels up for sale.
Defence Minister Gerry Brownlee said the government was looking for a buyer, and would most likely sell the two ships, because they could not handle the big seas beyond New Zealand's 12-mile limit.
Labour questioned why the government would use "inshore" patrol vessels in the waters known as the Exclusive Economic Zone (EEZ), when there was still a need for patrolling around the coast.
The inshore patrol fleet was commissioned more than 10 years ago after a review identified the need for fisheries protection, border control and search & rescue.
The navy has said in the past it could not put the whole fleet to sea because of a lack of skilled personnel.
Mr Brownlee said eight of the 11 inshore patrol vessels were in good shape, were at sea and were fully operational.
He said one was in the middle of its "mid-life" refit, which left two that had not been to sea for some time.
Mr Brownlee said they could be crewed if necessary, and denied there was an attrition problem in the navy.
But he said once the ships get into the EEZ, the conditions became too challenging.
"So we've got of course the Southern Ocean, a very big expanse of the Pacific to the east, and the Tasman to our west.
"As you get further into some of the island countries, or perhaps into the coastal areas around Europe, these would be very good vessels to have."
He said the government wanted to find a buyer for them and that process will begin.
"Remember that all military procurement, right at the time you purchase them, as disposal conditions, we've got to meet all of those as well."
Labour's defence spokesperson, Phil Goff, said there was a reason they were called "inshore patrol vessels".
"These ships are not designed for the high seas. We have offshore patrol vessels that go down to the Southern Oceans and up into the Pacific.
"The advice that the minister is giving totally contradicts any information that we've received from the Defence Force over the last three or four years."
Mr Goff said he found it hard to believe the sale would be because of the ships' capabilities.
"The select committee has received the opposite advice, the select committee has been told repeatedly by the Defence Force that the reason the ships are not at sea is they don't have the skilled staff to crew them after the huge attrition of 25 percent of the navy leaving in one year, in 2012, there's a massive skill shortage."
Minister for Primary Industries, Nathan Guy, said fisheries protection was a joint effort between the air force, on boat fisheries, intelligence information and the navy.
He would not offer an opinion when asked if the sale of two patrol vessels would compromise that capability.
"I'm not prepared to speculate on that, at the moment we've got a very good approach, we work across all of the government, we work across with other countries sharing intelligence, we share a huge amount of information so we
The defence spokesperson for New Zealand First Ron Mark said he still believed the ships did not have the crew to put them to sea, which could not be good for protecting New Zealand's fisheries.
"It stands out to me that we are not resourcing the navy, that the operational resourcing is set too low, that the instructions that they've received to save money and generate a surplus has cut into them - essentially this National government has scuppered the Navy."
Prime Minister John Key said it made sense to sell the vessels, if they were not being used.
"Ultimately the navy has to make sure that the assets they own are the ones that they use.
"There can be a variety of reasons why sometimes they don't use the assets they think they need. If they're not using an asset they are better to sell it and recycle that capital somewhere else."