Boatswain's call said to have been used at the Battle of Trafalgar.

The call is made of white metal with some original gilding. The buoy has a foul anchor at each side. There is elaborate scrolling foliage on the keel. The gun is inscribed ‘Trafalgar’ and the buoy is inscribed: 'JS MARTIN BOS. MATE HMS BRITANNIA'.

It was formerly the property of James Martin who became 'Yeoman of sheets' in the 'Britannia' in 1803. He was appointed Boatswain's Mate in1804 and served at Trafalgar.

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 calls like this one made suitable gifts and presentation pieces.