According to the sleeve notes of Gary Shearston's album Australian Broadside (1965),
[the] song was his response to the sinking of the destroyer Voyager by the aircraft-carrier Melbourne during naval exercises. The song […] “was written two days after the disaster out of a complete feeling of helplessness and frustration that eighty-two men had lost their lives rehearsing for this thing called war which was supposed to have ended twenty years ago for all time.”
Trevor Lucas sang The Voyager in 1964 on the album Australian Folk Festival. The album's sleeve note state:
This song was written by Gary Shearston who also sang it at the concerts. On this disc sung by Trevor Lucas (Melbourne) as Gary could not get released from his recording contract.
The Voyager on Trevor Lucas first Australian solo album of 1964, See That My Grave Is Kept Clean, is another song by Garry Kinnane about the same incident. Lucas commented in his liner notes:
The Voyager was written by a mate of mine, Garry Kinnane, who says that talking about total disarmament is too idealistic in this day and age, but as long as we're stuck with the curse of war machines, let's at least make sure they are made safe to operate.
Thanks to Alistair Banfield for the information on the LP Australian Folk Festival.