The Post Office provides marine communication services from four coast radio stations.

These stations, Auckland Radio/ZLD (Musick Point), Awarua Radio/ZLB (near Invercargill), Chatham Islands Radio/ZLC and Wellington Radio/ZLW maintain continuous listening watches on one or all of the international distress frequencies and provide radiotelegraph (morse) and radiotelephone communication for the exchange of telegrams with ships at sea around the New Zealand coast and with lighthouses and remote localities.

In addition, Awarua Radio is the main receiving and transmitting station providing world-wide morse communication with ships. Remotely-controlled transmitters, located at Himatangi (near Foxton) are used for this service.

Chatham Islands Radio also conducts the public telegraph and radiotelephone service with the mainland of New Zealand.