In the days of sail, orders aboard ship were piped on the Bosun's Call, whose high-pitched whistle could be heard against the strongest wind. 4" long, with matching 50" neckchain fitted with a swivel snap-hook. They are supplied in a presentation box, instruction leaflet and history. ENGRAVING - calls are engraved on the keel in classic copperplate script. Popular messages include a name and service number, ship's name or commemorative event. Maximum is two lines each side, of up to 18 characters or spaces (total 36 - capitals count as two).