Buoyage

The world uses a single system of buoyage, internationally recognised and created by the International Association of Lighthouse Authorities, to guide and advise ship traffic. There are two defined regions, IALA A and IALA B.

180 150W  120W  90W   60W   30W  000   30E   60E   90E   120E  150E 180
|    |     |     |     |     |    |     |     |     |     |     |     |
+90N-+-----+-----+-----+-----+----+-----+-----+-----+-----+-----+-----+
|          . _..::__:  ,-"-"._       |        ,     _,.__             |
|  _.___ _ _<_>`!(._`.`-.    /        _._     `_ ,_/  '  '-._.---.-.__|
|.{     " " `-==,',._\{  \  / {)     / _ ">_,-' `                  - _|
+ \_.:--.       `._ )`^-. "'      , [_/(                       __,/-' +
|'"'     \         "    _/       /| ,--'           A          /. (|   |
|         |     B     ,'         _)_A  ._<>                _,' /  '   |
|         `.         /          [_/_'` `"(                <'}  )      |
+30N       \\    .-. )          /   `-'"..' `:._    A     _)  '       +
|   `        \  (  `(          /         `:\  > \  ,-^.  /' '         |
|             `._,   ""        |     A     \`'   \|   ?_)   B         |
|                `=.---.       `._._       ,'     "`  |' ,- '.        |
+000               |    `-._        |     /          `:`<_| --._      +
|                  (   B    >       .     | ,          `=.__.`-'\     |
|                   `.     /        |     |{|              ,-.,\     .|
|                    |   ,'          \   / `'            ,"  A  \     |
+30S                 |  /             |_'                |  __  /     +
|                    | |                                 '-'  `-'   \.|
|                    |/                                        "    / |
|                    \.                                            '  |
+60S                                                                  +
|                     ,/           ______._.--._ _..---.---------._   |
|    ,-----"-..?----_/ )      _,-'"             "                  (  |
|.._(                  `-----'                                      `-|
+90S-+-----+-----+-----+-----+----+-----+-----+-----+-----+-----+-----+
Map 1998 Matthew Thomas. Freely usable as long as this line is included

This map shows which areas use IALA A and B. The only difference between the two regions is the colour of buoyage used when coming in and out of port.

Types of buoys
• Cardinal Mark
• Isolated Danger
• Emergency Wreck
• Port Buoy
• Starboard Buoy
• Safewater Mark
• Preferred Channel to Starboard
• Preferred Channel to Port
• Special Mark

Starboard Buoy

Purpose: Marks the starboard side of a channel.

Colour: Green in IALA A, Red in IALA B

Topmark: Cone

Light Colour: Green in IALA A, Red in IALA B

Light Pattern: Green in any pattern except Fl(2+1) (Reserved for Preferred channel Marker)

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Starboard Markers in IALA A. Note the Cone topmark on the Spar and Pillar shaped buoy.

Port Buoy

Purpose: Marks the port side of a channel.

Colour: Red in IALA A, Green in IALA B

Topmark: Can

Light Colour: Red in IALA A, Green in IALA B

Light Pattern: Red in any pattern except Fl(2+1) (Reserved for Preferred channel Marker)

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Isolated Danger

Purpose: Marks an area of danger below the buoy.

Colour: Black and Red

Topmark: Two Black Balls

Light Colour: White

Light Pattern: Flashing Group 2

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Preferred Channel to Port

Purpose: Marks the Starboard side of a channel as well as the main channel for shipping traffic.

Colour: Green Red Green in IALA A, Red Green Red in IALA B.

Topmark: Cone

Light Colour: Green in IALA A, Red in IALA B

Light Pattern: Flashing 2+1

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Preferred Channel to Starboard

Purpose: Marks the Port side of a channel as well as the main channel for shipping traffic.

Colour: Red Green Red in IALA A, Green Red Green in IALA B.

Topmark: Can

Light Colour: Red in IALA A, Green in IALA B

Light Pattern: Flashing 2+1

Special Mark

Purpose: Can be used to mark anything, check local chart.

Colour: Yellow

Topmark: Cross

Light Colour: Yellow

Light Pattern: Anything that cannot be confused with white lights (eg. Flashing 6 + 1 Long Flash) since yellow is similar.

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