Day beacon

This channel is designated by day beacons, though beacons "6" and "9" are omitted. Simple, unnumbered piles are used instead of them.

A day beacon is an unlighted nautical sea mark. Typically, day beacons supplement channels whose key points are marked by lighted buoys. Day beacons may also mark smaller navigable routes in their entirety. They are the most common aid to nautical navigation as they are relatively inexpensive to install and maintain, and unlike buoys, their position does not change as they cannot drift.

Identification

Day beacons, as with other lateral marks, are generally paired. When proceeding from open water towards harbor, odd-numbered beacons are kept to starboard (right facing abow) of the vessel, with even-numbered aids to port. As with other lateral marks, when sailing from the eastern (using "System A") to the western hemisphere ("System B") of the globe or vice versa, this system of numbering is kept upright. The combination of colours and shapes is however exactly opposite in the two regions. This principle ensures that a vessel which leaves a port in one region and later approaches a harbour in the other one, will always have the same colour with the same style of numbering on its sides along its course.

General placement

Navigation around day beacons is the same as with all other navigational aids. When beacons are paired, vessels should pass between the pairing. However, beacons are also commonly placed individually. Generally, single beacons are at the inside corner of a turn. However, single beacons are also occasionally placed outside a turn. Interior or exterior placement can be determined based upon the passing side (port or starboard) dictated by beacon designation. In either case, common practice is to approach the beacon as close as is prudent under the assumption that the beacon itself is in channel-depth water. However, current charting should always be consulted for all but the shallowest-draft vessels, as channel conditions are rarely ideal. This is particularly necessary when encountering non-standard beacons such as those neither red nor green.

Identification on charts

Because color standards vary internationally, beacon number is the best way to identify beacons on charts. Additionally, charts may be limited in color and not show red and green beacons directly as such. When color is not immediately apparent, a red beacon is typically shaded white with an "R" in its designation. More frequently, green is omitted from charts, and a green beacon is rendered black with a "G" in its designation.

See also

• Bowditch's American Practical Navigator
• Cardinal mark
• Daymark
• Safe water mark
• Isolated danger mark
• Special mark
• Lighthouse
• Foghorn
• Lightvessel

References

• US Chart No. 1: Symbols, Abbreviations, and Terms
• NOAA Historical Chart Archive