I found an old photo of my Grandfather tin naval uniform 1st world war , he`s wearing a hat with HM minesweeper i can`t find why its HM not HMS and how can i find his nave service record
It is because of the size of the ship. Ships in the Royal Navy are known as HM Ships, though formerly when a distinction was made between three-masted ship-rigged ships and smaller vessels they would be called HM Frigate X, or HM Sloop Y. Hope this helps