A search in Ancestry.com.au for information about one of Norman's older brothers shows that Robert Dugald Smith had returned to England where he obtained his 2nd Mate's certificate in the Merchant Navy in 1889 and a Master of Foreign Going Ships certificate in Merchant Navy in 1895. By 1903 Robert was back in Australia as the captain of a ship carrying coal between Wollongong and Sydney.
One can only suppose that some years later, Norman also decided to try his luck in England and ended up working on trawlers out of Hull. Hull was an important port for fishing and by the outbreak of the First World War many steam trawlers were stationed at the port. A Google search 'Hull trawlers' and similar headings provided articles relating to the trawlers and the fishing industry.
Trawlers at War - World War One provides the following information:
During 1907 Admiral Lord Charles Beresford recommended that steam trawlers be used in the role of minesweepers in the event of war. This would free up warships for other, more appropriate, duties. With the outbreak of WW1 in 1914, many of Hull's trawlers were requisitioned for minesweeping and anti-submarine duties. Around 800 trawlers from the Hull and Grimsby fishing fleets and a new rank, Skipper Royal Navy Reserve, introduced for trawler skippers who, quite naturally, had no regard for regular Navy discipline.
Only around one quarter of the Hull fleet remained on fishing duties and the North Sea fisheries placed out of bounds due to the dangers of enemy action. Fleeting was suspended and the 'boxer fleets' of Helyers and Great Northern were put to single-boat fishing. Although the overall effect was that the supply of fish dropped nationally, Hull's share of the British catch actually increased as the Barents and Icelandic fishing grounds remained open.
By the end of the war, over 200 British trawlers had been lost along with 50% of their crews. The surviving ex-Navy trawlers were offered for sale and refitted for a return to fishing.
A Google search for 'Skipper Royal Navy Reserve' also leads to web pages providing additional information:
Lists of the trawlers from Hull that have been sunk or wrecked are available online but I have not yet located information about Norman. For some sites it is necessary to know the year or name of the vessel and I have not yet had time to undertake such a search.
We may never know what really happened to Norman McCallum Smith but the search has led to locating another aspect of the history of World War I.