Residents on the Cocos (Keeling) Islands have been warned that homes are under threat after a tidal surge slammed the remote territory's western side.
Swells measuring up to 3.5 metres were recorded from Monday evening into Tuesday morning, overwhelming concrete seawalls and coastal sandbagging on the islands, which are Australia's most remote territory.
Heavy waves and high tides have hit the Cocos (Keeling) Islands. (Supplied: Shire of Cocos (Keeling) Islands)
A deep low-pressure system in the Southern Ocean pushed the surge towards the tropical tourist destination, located almost 3,000 kilometres north-west of Perth in the Indian Ocean.
All beaches on West Island and the South End Road, the only road to the island's southern tourist area, have closed until further notice.
Australian Federal Police are advising new arrivals of the situation at the airport, with all tours suspended.
Shire chief executive Frank Mills said the scale of the waves was "totally unprecedented", even for long-term residents.
"Monday night … was absolute freak [in size]," he said.
"The water was of such a magnitude it actually came well over the top of the seawall and totally destroyed them.
"I've never seen anything like it."
Swells measuring up to 3.5 metres have been recorded. (Supplied: Shire of Cocos (Keeling) Islands)
Threat remains
While the swells abated on Tuesday, the Bureau of Meteorology has warned the tide is yet to peak.
"Tides are at their highest during the month when it is a full moon and new moon, and it is approaching full moon tomorrow [Thursday]," meteorologist Caroline Crow told the ABC.
"[It] could cause water over the roads and impact the southern end of the West Island."
The shire says some sandbags were washed away. (Supplied: Shire of Cocos (Keeling) Islands)
The Shire of Cocos (Keeling) Islands expects the tide to reach as high as 1.7 metres on Saturday, with swells of nearly a metre high.
Mr Mills said the failure of seawalls and sandbagging had exposed the islands' vulnerability to extreme weather events.
Most worrying, he explained, was how close the water came to breaching a generator at the West Island medical clinic.
"The last thing we want is the generator going underwater or getting affected by water because that'll put all of the … life-saving equipment in the clinic out of action," he said.
"Being in such a remote location, we can't afford to have that happen."
The Cocos (Keeling) Islands are a remote tropical tourist destination in the Indian Ocean. (ABC News: Chris Lewis)
Calls for government support
Mr Mills said residents will have to wait for the tide to recede before they can gauge the extent of the damage.
He called on the federal government for greater support heading into cyclone season.
"My biggest concern is the lack of buy-in from the Commonwealth to provide any sort of funding to do any recovery works and also to do any resilience works," Mr Mills said.
Frank Mills says the Commonwealth needs to do more to help. (ABC Pilbara: Alice Angeloni)
The shire submitted a $18.5 million application to construct and reinforce seawalls, which it said would have reduced the risk to homes.
The federal government recently rejected that submission, according to Mr Mills.
"The concrete seawall that's had its integrity broken … there's no one here on the islands with any expertise to do that," he said.
"[It] could be a disaster time for the Home Islanders and certainly parts of West Island will go underwater."
The Administrator of the Indian Ocean Territories has been contacted for comment.