Boxing the compass is the action of naming all thirty-two principal points of the compass in clockwise order. It was also used as in naval slang as a description of a ship (typically one that had lost a rudder or had no one manning it) slowly revolving in a calm sea in a "directionless" manner, thus pointing through all of the compass points, sometimes reversing itself.
Such names, formed by the initials of the cardinal directions and their intermediate ordinal directions, are accepted internationally, even though they have their origin in the English language, and are very handy to refer to a heading (or a course) in a general or colloquial fashion, without having to resort to computing or recalling angle numbers. Despite the name of the 1959 Alfred Hitchcock movie, North by Northwest, there is no such direction. However, old-timers allow three letter directions to have a 'by' inserted beween the first and second letter. Hence, NNW becomes North by Northwest, per Hitchcock's title.
A simple algorithm can be used to convert a heading to an approximate cardinal direction:
A heading of 75°, divided by 45 gives 1.67, multiplied by 4 gives 6.67, added to 0.5 gives 7.17. 8 in the table below corresponds to east by north.
|#||Compass point||Abbr.||Traditional wind point||True heading|
|2||North by east||NbE||11.25°|
|4||Northeast by north||NEbN||33.75°|
|5||Northeast||NE||Greco or Bora||45.00°|
|6||Northeast by east||NEbE||56.25°|
|8||East by north||EbN||78.75°|
|10||East by south||EbS||101.25°|
|12||Southeast by east||SEbE||123.75°|
|14||Southeast by south||SEbS||146.25°|
|16||South by east||SbE||168.75°|
|18||South by west||SbW||191.25°|
|20||Southwest by south||SWbS||213.75°|
|22||Southwest by west||SWbW||236.25°|
|24||West by south||WbS||258.75°|
|25||West||W||Poniente or Zephyrus||270.00°|
|26||West by north||WbN||281.25°|
|28||Northwest by west||NWbW||303.75°|
|30||Northwest by north||NWbN||326.25°|
|32||North by west||NbW||348.75°|