Silver boatswain's call, the keel with wrigglework decoration, including an anchor design, and a scroll end. An initial 'M' is stamped on one side of the keel. The rounded buoy has a foul anchor at each side.

The boatswain's call has a long history both as a symbol of office and as a practical instrument for conveying orders at sea. Its distinctive shape has remained practically unchanged from medieval times to the present day. The call's shrill whistle can be varied in pitch to convey a variety of information, and can be heard above the sound of wind and sea. Such instruments were private possessions rather than official equipment and silver calls like this one made suitable gifts and presentation pieces.