The Government is denying accusations by New Zealand First that the navy was too passive in its Southern Ocean stand-off with toothfish poachers.
Defence Minister Gerry Brownlee said such criticism was ill-informed and the operation had actually been a success.
Equatorial Guinea gave permission for New Zealand to board three fishing ships to verify their flagged status, after agreeing they were illegally fishing for toothfish in Antarctic waters.
Yesterday, crew on HMNZS Wellington were refused entry to the vessels by the captains, and did not forcefully enter because it was deemed to be too dangerous.
New Zealand First's defence spokesperson Ron Mark said the Navy's "toothless" response to the illegal toothfish fishing was an embarrassment. He said a literal shot across the poachers' bows was what was required.
"How we behave right now will determine how poachers and pirates treat us in the future," he said.
"If they perceieve that our navy is toothless, if they perceive that our Government is gutless they will just give us the bird and sail away. When, quite frankly, right now a burst of gunfire would end it all."
'We're not talking about starting a war'
Defence Minister Gerry Brownlee said Mr Mark's claims were nonsense.
"Look, remember that we're talking about illegal fishing, we're not talking about starting a war ... I think the captain of the Wellington made an assessment about the weather conditions and about whether or not there could be a safe boarding of those ships," he said.
"I'm not down there, Mr Mark is certainly not down there and I think the captain who had all the authority necessary to make the decision has done the right thing."
He said the information the navy had gathered about the vessels would make it very hard for them to sell their catch.
Listen to Gerry Brownlee and NZ First's Ron Mark on Five O'Clock Report
Fishing company Sanford - which is one of two New Zealand companies licensed to catch toothfish in the Ross Sea - has welcomed the navy's monitoring of the three vessels.
The company's chief operations officer Greg Johansson said illegal fishing posed a threat to the environment, fish stocks and also the crew on the poaching vessels.
But he said it could backfire on New Zealand if the navy tried to use force or arrest the boats' captains.
"You know, if they can't establish some evidence that those vessels fished inside the exclusive economic zones of, for example, Australia or have breached some convention that their flag state are party to, it could be very embarrassing for New Zealand," he said.
"So they do have to tread carefully and slowly and work with other governments to make sure they've crossed all their 'i's and dotted all their 't's before they go charging in."
Mr Johansson said the best way to deter poachers was to stop them selling their catch.
"Along with enforcement on the water, it's about monitoring what they do afterwards and controlling their market access so the key markets like the US already have strong measures in place," he said.
"It's another way to cut off their cash supply by restricting their access to the high-price markets."
Mr Johanson said the presence of the New Zealand navy in the Southern Ocean would act as a significant deterrent for illegal fishers.
Stand-off in the Southern Ocean
HMNZS Wellington intercepted two foreign fishing boats in the area last week- the Kunlun and the Songhua.
The Wellington also caught another ship this week - Yongding - which was thought to be part of the same fishing syndicate.
Peter Hammarstedt, the captain of the Sea Shepherd vessel Bob Barker, said earlier that the poachers had been trying to outlast the Wellington's fuel supply.
He said the New Zealand ship was outnumbered three-to-one and Australia needed to send a vessel to help.
"Where is the Australian government in all this? We do know that the Australian government committed to, earlier this year, sending down a customs vessel, they have not done so to date," he said.
"Now is the the time for the Australian government to send the New Zealand vessel the support it needs."
Mr Hammarstedt also said more needed to be done to punish the poachers.
"Enough will be when these vessels are taken into custody, these vessel have been operating illegally for the past ten years now in the Southern Ocean.
"We can't have them just getting a slap on the wrist. The New Zealand Government has to slap the cuffs on them, take them back to port and detain these ships permanently."
Listen to Peter Hammarstedt on Summer Report
Regulations on harvesting toothfish are managed by international organisation CCAMLR (Commission for the Conservation of Antarctic Marine Living Resources).
The commission was established by international convention in 1982 with the objective of conserving Antarctic marine life.
Its 25 member nations agreed to strict rules including catch limits and reporting fishing data,
The commission's stance was that any non-member state fishing in the area was doing so illegally.