| There is no internationally agreed symbol, but the symbol kn is commonly used | |
|---|---|
| Wilson, Alastair 22 July 2009 | Weights and Measures Standards of the United States, A brief history |
Since the 1890s or thereabouts, it has been drummed into the young seaman that a knot is a unit of speed, namely, one nautical mile per hour; and that consequently only the uneducated speak of "knots per hour" or "knots an hour".
29.