HMS Clan MacNaughton was a converted 4,985 ton cargo passenger ship built in 1911 for the Clan Line Steamers, Glasgow. The vessel was hired by the Admiralty in November 1914 and fitted out in London with eight 4.7" guns and was in service at Liverpool by 4 December 1914.

She operated as part of the 10th Cruiser Squadron and was sunk during a severe gale (or possibly mined) off the NW coast of Ireland with the loss of all hands - 20 Officers and 261 ratings.

The true cause of her sinking has never been fully established. However, there has been some speculation that a combination of a bad Atlantic storm, coupled with a top heavy ship (due to the fitting of naval guns) and an inexperienced and ill balanced crew may have contributed to her loss rather than a loose mine out in the Atlantic. The crew was made up of a mix of reservists (many from Newfoundland), a RMLI detachment, mercantile sailors, some RN regulars and a large number of boys (50) straight out of training school.

In the month following the loss a Question were raised in the House of Commons on the subject of the ship's stability with regard to the fitting of the guns. The Admiralty reported that they had been satisfied as to the stability of the vessel.