For other ships of the same name, see HMS Gleaner. HMSML Gleaner (H86) is the smallest commissioned vessel in the Royal Navy with a length of just under 15 metres and a ship's company of just 9 (2 officers, 1 Senior Rating and 6 Junior Ratings). She is currently based in Devonport, Plymouth.The ship prefix HMSML stands for Her Majesty's Survey Motor Launch.or other ships of the same name, see HMS Gleaner. HMSML Gleaner (H86) is the smallest commissioned vessel in the Royal Navy with a length of just under 15 metres and a ship's company of just 9 (2 officers, 1 Senior Rating and 6 Junior Ratings). She is currently based in Devonport, Plymouth.