Dear Shem, all the Dolphin Class and Mariner Class vessels were actually built as composite gunvessels. The two Dolphin Class vessels were reclassified as sloops while building, and the 'six 'Mariner'' class vessels were reclassified as sloops on 26 November 1884. The normal practice is to list them under the type of vessels they were originally, so I suggest that you include both classes with the Lists of gunboat and gunvessel classes of the Royal Navy. I also suggest that the articles on the eight individual vessels (some of these may not yet have been written!) should be amended accordingly.