Clean sweep (naval)

A "clean sweep" for a naval vessel is having "swept the enemy from the seas", a completely successful mission.

It is said the use of brooms in this respect originated during the 1650s, when the Dutch Admiral Maarten Tromp, after a decisive victory in the First Anglo-Dutch War, the Battle of Dungeness of 1652, hung a broom from his mast to indicate he had "swept the British from the seas" - his opponent Admiral Blake is said to have responded with the hoisting of a whip, indicating he would whip the Dutch into submission.

[1] The United States Submarine Service during World War II generally considered a patrol a "clean sweep" if the sub sank every target she engaged.

[2] Individual torpedoes might miss, and convoys usually had far too many ships for all to be sunk by a single boat, but these unavoidable inefficiencies did not mar a "clean sweep".

[3] In 2003, under circumstances perhaps closer to the traditional context, after USS Cheyenne and USS Pittsburgh (SSN-720) launched their Tomahawk missiles during Operation Iraqi Freedom,[4] her commanding officer decided that placing all missiles on target, with no duds or failures, was a modern "clean sweep".