Here's a couple of pages identifying Taiwa as D.H.Rogers.
AT SEA (John Smith AB)) Words: D.H. Rogers (1904) The Bulletin The entries in ships’ logs, listing only the time and place of a sailor lost at sea, are the basis of this song, published in The Bulletin under the pen-name of Taiwa M.L. (taiwa means ‘spud’ or ‘foreigner’ in Maori & M.L. is Maori Land.) Rogers was a Dunedin accountant, writing for Sydney papers at the same time as Henry Lawson and Banjo Paterson.
& David Hunter Rogers was born in Edinburgh in 1865. He came to Dunedin in 1870 when his parents migrated from Scotland by a memorable voyage on a windjammer, and from the ages of 15 to 35 he gained considerable experience in the mercantile marine, but working on shore, as an accountant for the Union Steam Ship Company! As a young man he would have undoubtedly been been told many stories by the old windjammer sailors, and these influenced him greatly in later life.
He joined a shipping company because he loved the speedy windjammers, but 1870-1900 was a time of rapid change when wooden ships with sails and small auxiliary steam engines gave way to to more efficient steel tramp steamers, and as a shipping company's accountant, he had to sit at board meetings and present figures showing why sailing ships could no longer be used.
In 1894 he married Eliza Jane Nimmo, a school teacher aged 29, and they had 2 children. Later he was an accountant/secretary for various Otago companies, and as the aches and pains of an ageing body in a cold, damp came to him, the verses (such as Homeward Bound, Chanties, Seafarers, Hulks, and Seabirds) mostly published in The Bulletin under the pseudonym of Taiwa ('potato' in dialect Maori) show a romantic yen for the life of those windjammer sailors:- of high adventure on a story ocean, and a sudden painless death in the prime of life.
He became ill at the age of 60, resigned his secretaryships of the St John's Ambulance, Navy League, DIC, etc, made a visit to London with his wife and daughter, and in 1933 he died at his hilltop home 12 Pacific St, Dunedin, aged 68. His wife died in 1946.