Dropping you in my beautiful new cache! Safe travels!
I’m so glad I ran this through Google Translate
"A boatswain's whistle (also a boatswain's whistle) is a metal signal whistle that is used on board ships.
In the era of the tall ships, the boatswain's pipe was used by the boatswain to pass commands on to the ship's crew. Roman oarsmen are said to have been commanded by whistles since ancient times; in their present form, the boatswain's whistle was first used on English sailing ships in the 13th century. Although it only knows the two pitches "high" and "low", certain signal sequences included a large number of different commands. The loud and shrill sound drowned out the weather, the sea and the ship's own noises and interrupted any conversation on board.
The construction of the pipe is simple and contains no moving parts, but using it requires some practice. The air flow is blown into a narrow tube via a mouthpiece, from the end of which it hits an open ball at high speed. The edge of the ball opening serves as a labium, similar to that of an organ pipe. By blowing differently and changing the hand position, the tone can be varied when whistling. A basic distinction is made between the beeps "high" and "low", the duration of the tone and its sequence, and trills are also used.
The instruments are made of metal, mostly copper and brass. Silver-plated and solid silver versions are also available and a golden pipe became the insignia of the highest British admiralty in 1670. The pipes of the German Navy are made of nickel-plated brass. Depending on the level of service of the user, they are also called mate or boatswain's mate pipes.
In today's shipping, commands are passed on to the crew via loudspeakers, megaphones or on-board radio and the boatswain's whistle only plays a greater role in the on-board ceremony on military ships. Every officer and dignitary who goes on or off board is entitled to a signal of reverence: "Whistle". The pipe is also used in the flag parade. In contrast, the "front" is whistled by the officer on watch with the battery whistle. It is also traditionally used on sailing school ships such as the Gorch Fock, where orders are still given or announced by whistles. "