Aotearoa's first-ever nationwide tsunami evacuation map is now live online, so Kiwis can figure out if they are at risk and what to do if they are.
It's the next step in the Government's plan to get people better prepared for tsunamis.
And large yellow buoys are responsible for alerting authorities when a tsunami is on its way.
"That's all it takes to measure the pressure," said NIWA chief scientist Mike Williams.
The pressure indicates if the water's depth is changing.
"We can look at how long that's happening for and determine if it's just a big wave from a storm, or if it's a tsunami."
The pressure recorder sits on the sea floor, sending signals to the surface buoy that then fires it up to a satellite.
Twelve of the systems are in the ocean surrounding Aotearoa, New Caledonia and the Kermadec Trench.
"New Zealand's got the second largest network after the US," Williams told Newshub.
A network that's feeding data into a brand new map on getready.govt.nz, which can tell you if your home is in a tsunami risk zone.
And it's the first map of its kind for the whole country.
"Then when people get a warning, if they've looked at the maps and got prepared they'll know how to act - every second counts in these situations," Emergency Management Minister Kieran McAnulty said.
"The map has been developed by the National Emergency Management Agency in close partnership with the 16 regional Civil Defence Emergency Management Groups."
The Emergency Management Minister's urging all Kiwis to check out the new map.
"You'll be able to help yourself if you get prepared early."
The map will also identify tsunami 'safe zones' marked in some places by a blue line.
A blue line Newshub visited shows the maximum reach of a tsunami in Wellington's Lyall Bay, a community initiative that's been so successful it's now being rolled out nationwide.
"We're now looking to standardise it so we've all got exactly the same data and measurements to identify where that blue line is," said Wellington Regional Emergency Management Office regional manager Jeremy Holmes.
Tsunamis are something Tutukaka in Northland is far too familiar with. Tonga's January eruption sent large and damaging waves into the marina, but no alert siren sounded beforehand.
Dive Tutukaka's Kate Malcolm said this could have resulted in the loss of lives.
"We were lucky that we didn't lose any lives because there were people in boats, people falling off the marina."
Malcolm welcomes the new evacuation map but wants better alert systems as well.
"Come have a chat with us in the community and see what things we need to change," she said.
So that tsunami risks are effectively communicated from the buoys to seaside communities.
