Silver boatswain's call with a barrel-shaped buoy embossed with a crown and anchor device at each side. The gun has three reeded bands and another at the mouthpiece. The keel is decorated with engraved foliage designs and terminates in a scroll. There is a ring in the keel for attachment to a lanyard.

The call was used by the boatswain of Admiral the Hon. Sir Montagu Stopford (1798-1864), whose grandson donated it to the Museum.

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.