Hastings Civil Defence is advising coastal residents to self-evacuate and for people to stay away from beaches, as reports of tsunami of at least 30cm come in from Chatham Islands.
The latest prediction is that waves could hit Hawke Bay from 8.53am.
Police and the fire service are currently door-knocking in the coastal communities of Te Awanga, Haumoana, Clifton and Whirinaki.
Haumoana School is open as a welfare centre and around 80 people have already self-evacuated to the school.
Waimarama and Ocean Beach residents have already been advised to self-evacuated.
Civil Defence volunteers have reported a stream of vehicles heading toward beaches to see the tsunami but authorities are strongly urging people to stay away from the waterfront.
The tsunami was sparked by an 8.8 richter scale earthquake which struck 90km from the coast of the Chilean city of Concepcion at a depth of 35km.
Hastings District Council activated its Emergency Operation Centre just after midnight.
Boaties are advised to take boats already in the water out to a depth of 30m or more and emergency services have closed boat ramps along the coastline as a precaution.
Estimates from the Ministry of Civil Defence and Emergency Management are that any wave hitting Hawke Bay is likely to be less than one metre in height.
However, the first wave may not be the biggest with waves possibly continuing for between six and 12 hours after the initial wave.
The CDEM national advisory advises people should:
Stay off beaches
People should not go sightseeing in coastal areas
Stay away from coastal areas including, tidal estuaries, rivers and streams for 24hours, as even small waves create dangerous currents
Boats are generally safer in water deeper than 30m than closer to shore
Share this information with family, neighbours and friends
Listen to the radio or television for updates
Follow the instructions of local Civil Defence