sentences:  Fifty were ordered for the RNAS, of which only 37 were completed.The Converted Seaplane entered service with the RNAS in 1917, operating from bases at Calshot, Dover, Portland and Cherbourg.On 18 August 1917, a Wight Converted Seaplane flying from Cherbourg sank the German U-boat with a single 100 lb bomb, the first submarine to be sunk in the English Channel by direct air action.