In 1917 the yacht was purchased by the Royal Australian Navy (RAN) and used as the auxiliary patrol vessel HMAS Sleuth in the waters around the Torres Strait and Thursday Island, before later being used as a training ship tender based in Sydney.

Based in Hobart and under different owners SY Ena was used for a number of purposes including transportation of produce and fishing.

[1][2] The vessel was designed by Walter Reeks (1861–1925) a Sydney naval architect based in Pitt St, who had come out from the UK in 1885.

[3] Its elegance and construction were recognised in a 1906 (American) Rudder magazine story on the vessel, and looking at it in retrospect, the steam yacht shows that Australian designers and shipbuilders could build luxury craft to the same quality and standards as in Europe or North America[1] in this period of classic yachts.

[2] SY Ena was purchased by the Royal Australian Navy (RAN) in January 1917 for A£1,000, and converted for use as an auxiliary patrol vessel around the Torres Strait and Thursday Island, armed with a QF 3 pounder Hotchkiss gun on the foredeck.

[2] It proved unsuited for tropical patrol work, and Sleuth was later deployed along the Queensland coast, then relocated back to Sydney and assigned as a tender to the immobilised training ship Tingira.

It changed ownership a couple of times but under one owner William Longworth, it often travelled between Sydney and Newcastle.

The stem was reduced, a diesel engine was installed in 1945, and facilities for keeping fish (including refrigerated storage and a wet well) were fitted.