Australian border authorities may need to restructure their patrols following the undetected arrival of 66 Sri Lankan asylum seekers apparently hoping to find refuge in New Zealand.
Their appearance at Geraldton, north of Perth, shocked authorities whose attention is focused heavily on the northwest approaches to the mainland, where most boats are intercepted near Christmas Island or Ashmore Reef.
The boat, flying a New Zealand flag and displaying signs asking for help in getting to New Zealand, is believed to have followed a route that extended the normal time at sea by more than 40 days.
The boat is the first to have reached the mainland in five years.
Customs and Border Protection officials have told Home Affairs Minister Jason Clare the boat appeared to have sailed directly from Sri Lanka on a course far to the south of most Indian Ocean crossings.
"It's possible that the people on this boat took this southerly route because they were wishing to travel to New Zealand," Mr Clare told ABC radio.
"I've asked Customs and Border Protection to review the circumstances of this case and advise me whether there needs to be changes to the way in which we patrol the seas in the northwest.
"But 99.9 per cent of vessels that are intercepted are heading to either Cocos Island, Christmas Island or Ashmore Island ... because they're seeking the shortest trip possible.
"We'll need to better understand what the motivations were of the people on this boat."
The Sri Lankans have little hope of any early decision on their future.
Although New Zealand has agreed to include 150 asylum seekers from Australia in the annual refugee intake of 750, the arrivals are being flown to Christmas Island for processing.
Their situation is different from most of the other 4500 asylum seekers who have arrived since the start of the year because they avoided areas excised from Australia's migration zone and landed on the mainland.
Legally, this provides them with greater legal protection and rights.
Mr Clare said any approach to New Zealand about accepting the Sri Lankans would be a matter for the Immigration Department.
"If they don't meet the requirements of the Refugee Convention then they won't be going to Australia or to New Zealand," he said. "They'll go back to Sri Lanka."
Last year, 10 members of China's banned Falun Gong movement were rescued north of Darwin after their boat broke down en route to New Zealand. After officials explained the dangers of continuing their voyage, the group decided to apply for asylum in Australia.