Possible Clues:

• That's got three feet and one other limb on board
• The law's reach extending to maritime equipment
• Part of ship's sail support
• What's got three feet and one hand on board?
• My radar (anag)
• First drink, when sun over it
• Three feet on the wrong sort of limb on board.
• CID weapon found on board ship
• Three feet from shoulder to wrist on board
• End of spar on ship's mast