Complex sentence: All vessels of the Royal Navy bear the ship prefix "HMS"-Her Majesty's Ship-with the exception of "Gleaner" which bears the prefix "HMSML"-Her Majesty's Survey Motor Launch.
Split into simpler sentences: All vessels of the Royal Navy bear the ship prefix "HMS", for Her Majesty's Ship. An exception to this is "HMSML" "Gleaner", the prefix of which stands for Her Majesty's Survey Motor Launch.