Editing Cardinal mark (section)

== Characteristics ==
The characteristics and meanings of cardinal marks are as defined by the [[International Association of Lighthouse Authorities]].

A cardinal mark indicates one of the four compass directions by:

* the direction of its two conical top-marks, which can both point up, indicating north; down, indicating south; towards each other, indicating west; or away from each other, indicating east
* its distinctive pattern of black and yellow stripes, which follows the orientation of the cones - the black stripe is in the position pointed to by the cones (e.g. at the top for a north cardinal, in the middle for a west cardinal)
* optionally, its distinctive sequence of flashing light, which consists of a sequence of quick or very quick flashes whose number gives the [[clockface]] position which corresponds to the direction of the cardinal (e.g. three for an east cardinal, nine for a west; north has continuous flashes, and south may be augmented with a long flash, to help distinguish it from a west in difficult conditions)

{| class=wikitable
|+ Summary of mark characteristics{{sfn|IALA|2010|p=14}}
! Characteristic !! North !! South !! East !! West
|-
! Topmark
| ▲<br/>▲<br/>Both cones point upwards || ▼<br/>▼<br/>Both cones point downwards || ▲<br/>▼<br/>Cones point away from each other || ▼<br/>▲<br/>cones point towards each other
|-
! Colour
| Black above yellow || Yellow above black || Yellow horizontal band on a black body || Black horizontal band on a yellow body
|-
! Light (if fitted)
| Continuous flashes || 6 quick flashes + 1 long flash || 3 flashes || 9 flashes
|}

Either a quick or a very quick sequence of light flashes may be used; the choice allows for two similar nearby marks to be uniquely identified by their lights.

A cardinal mark may be used to accomplish the following:

*Indicate that the deepest water is an area on the named side of the mark
*Indicate the safe side on which to pass a danger
*Draw attention to a feature in a channel, such as a bend, junction, branch, or end of a shoal
*Draw attention to a new danger such as a grounded ship. In such cases two equal marks are often placed together to indicate that it's a newly marked danger and is not yet printed in official charts.

Other uses:

*Sometimes a Cardinal Mark can be used instead of a [[Special mark]] to indicate a spoil ground, or an outfall pipe for example. A few examples can be seen on the South Coast of [[England]] and in Northern [[France]].