A small number of Captains were converted to act as headquarters ships during Operation Neptune (the Normandy landings) and as coastal forces control frigates. Captains who operated with Coastal Forces (motor torpedo boats, motor gun boats and US Navy PT boats) sank at least two two-man submarines, and were involved in the destruction of at least 26 E-boats, one KFK patrol vessel (coastal escort vessels constructed so as to resemble a fishing-vessel), two minesweepers, and the shooting down of a Junkers Ju 88 aeroplane.