
This channel is designated entirely by day beacons, though beacons "6" and "9" are omitted.
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

This channel is designated by day beacons "18" and "20" as well as lighted buoys "16," "17," "21," and "22."
Day beacons, as with other aids, are generally paired. 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. Beacons are numbered in descending order from open water to harbor.
Region A
Region A comprises
Europe,
Africa,
Australia, and
Asia, with the exception of
Japan and the
Philippines. Within Region A, day beacons are characterized as follows:
Even-numbered beacons are characterized by:
★ Green color
★ Conical shape (floating, also known as a ''nun'')
★ Triangular shape (signpost)
Odd-numbered beacons are characterized by:
★ Red color
★ Cylindrical shape (floating, also known as a ''can'')
★ Square shape (signpost)
Region B
Region B comprises the
Americas,
Japan, and the
Philippines. Within Region B, day beacons are characterized as follows:

This primitive day beacon, designated "9A," comes from Region B as evidenced by a green odd number. The "9A" designation indicates that it has been placed as a supplemental marker between beacons "9" and "11."
Even-numbered beacons are characterized by:
★ Red color
★ Conical shape (floating)
★ Triangular shape (signpost)
Odd-numbered beacons are characterized by:
★ Green color
★ Cylindrical shape (floating)
★ Square shape (signpost)
A common mnemonic for remembering the appropriate characteristics (within Region B) is "an 'odd' 'can' of 'green' beans." Orientation can also be remembered via "red right returning," indicating that the red odd-numbered beacons should be kept to starboard when returning from open water to harbor.
General Placement

Irregular day beacons, such as this aground sailboat, should be given a wide berth.
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
★
Lighthouse
★
Foghorn
★
Lightvessel
References
★
US Chart No. 1: Symbols, Abbreviations, and Terms
★
NOAA Historical Chart Archive