Possible Clues:

• The end of support for sailing?
• Three feet and one hand at the end of it on board
• Detectives give weapons to stick on the mast
• Extremity of beam supporting a square sail
• Measure of ale and a case of rum - it's needed for sailing
• From which mutineers once swung?
• Three feet come to one handy end on board
• Part of a ship's superstructure
• Some feet and limb that one finds in marina
• Barmy army boxes tough cockney: a bit of a spar