Mr McGrath (96) spoke to the Otago Daily Times on his birthday yesterday about going to war as a young married milkman from Dunedin.
He volunteered for the army and in 1942 left his young wife Frances McGrath (nee Roberts) and their newborn son Robert to be a coastwatcher in Tonga.
Mr McGrath spent more than a year in the Pacific, watching the sea and sky for signs of Japanese troops. He said they did not reach Tonga, but came close.
The Japanese captured and executed 17 New Zealand coastwatchers on Tarawa Atoll, in what is now Kiribati, on October 15, 1942.
Those killed included Clifford Pearsall, of Lawrence, and Arthur Heenan, of Middlemarch.
Today at 11am a wreath-laying ceremony will be held at the National War Memorial in Wellington to mark the 70th anniversary of the execution and commemorate the service of all New Zealand coastwatchers.
Mr McGrath said coastwatchers did not receive much recognition after the war. Chief of the New Zealand Defence Force Lieutenant-general Rhys Jones acknowledged this, saying recognition was overdue.
After the war, Mr McGrath returned to Dunedin to work as a milkman and had a second son Keith.
Tonga had been Mr McGrath's first overseas experience.
Otago descendants of coast- watchers killed on Tarawa planned to attend today's service in Wellington.
