NARROW CHANNELS - RECOMMENDATIONS Vessels navigating within this area should be considered to be in Narrow Channels within the meaning of Rule 9 of The International Regulations for Preventing Collisions at Sea (1972). Skelmorlie Channel is a northbound channel for vessels with draughts in excess of 15 metres (50 feet). See Admiralty Sailing Directions for the appropriate day-signal to be displayed by vessels navigating within this area.