Friday Jun 9, 2023


Navigational Marks

Officer: Mr. Ramin Nourozi

Phone Number: 013-44992518

In order to provide safe navigation of vessels in channels, basins and coastal waters, Ports and Maritime Authority of Guilan Province has attempted to utilize lights and shapes suitable to the area to prevent incidents and also to guide the vessels towards a safe zone according to the international rules and regulations.

All matters related to lighthouses are derived from the enacted rules and regulations of International Association of Lighthouse Authorities (IALA) which are also enacted by IMO; all the countries that have joined these conventions are obliged to follow these laws. Therefore, the entire maritime zones throughout the world are divided into A and B regions and every country would register and announce its own AIDS to Navigation marks according to one of the foresaid regions in order to guide the vessels. The lateral signs in the Regions A and B are different but the other marks that are common in both regions.

AIDS to Navigation marks are divided into 6 groups:








Lateral Marks: Lateral marks are used to define the edge of a navigable channel, most commonly when entering/leaving ports. In the channels that are considered as A region, like those of Iran, the vessel would see red lateral marks on its left side and the green lateral marks on its right side. Obviously, the pattern will be reversed while leaving the port. 

Cardinal Marks: A cardinal mark indicates where the safest water may be found and is divided into four north-south-east and west marks; each mark specifies a safe direction for marine activities. For instance, if a vessel sees a west cardinal in its direction, it should select its direction so that it passes west of the west cardinal.

Isolated Danger Marks: these marks are used when a point in the sea is considered unsafe; for example, a wrecked vessel or a shallow point. In these cases the vessel shall avoid moving towards the specified point and continue to pass the way with keeping a safe distance from the point.

Safe Water Marks: this mark is usually seen in anchorages near the sea. It illustrates the safe zone in that region and vessels can pass all around its four directions.

Special Marks: this mark is used when a special region of the sea is confined and vessels are not allowed to perform maritime activities in that region. For instance, a region that is confined for military exercises will be announced to the entire vessels in the region so that they avoid maritime activities in that region.

EMERGENCY WRECK MARKING: can be used to mark a newly discovered vessel not yet shown in nautical documents. In other words, this mark is used to indicate the place of a new wreck until the exact place of the wreck and the water depth above the danger point are not recognized and the mark type is not determined.

Special structures are used to indicate AIDS to navigation marks in the points in question; some of the structures are as follow:

·         Some of these marks are in the form of vessels and are called BUOY; they are fixed in the sea by means of chains or weights.

·         Some of these marks are in the form of pillars fixed in shallow waters or near the shore and are called BEACON.

·         Another type of these kinds of structures exists in seashores and like Beacons are fixed on the ground by means of pillars; they are much bigger than Beacons in size and are higher in height. These structures are seen in various forms like Towers and Lighthouses that are called Pariahs.

·         In the points where due to the distance from the shore and the depth of the sea, using buoy is not appropriate and more focal height is required, bigger vessels like light boats or light vessels are used as the aids to navigation marks. Light vessels are also fixed by means of chains and anchors just like buoys.

These structures convey messages to mariners by means of characteristics such as color and day light throughout the day, color light and the number of times it flashes during a time period in nights.

The recognition of aids to navigation marks for the region A

1.     Lateral Marks

A.   Right hand channel:

·         Color of the mark: green

·         Day mark: single green conical shape that points upward

·         Flashing light: green

·         Light rhythm: composite group flashing (2+1)

A.   Left hand channel:

·         Color: red

·         Day mark: single red conical shape

·         Flashing light: red

·         Light rhythm: composite group flashing (2+1)


1.     Cardinal Marks

A.   North Cardinal:

·         Color: the top is black and the bottom is yellow

·         Day mark: two black conical shapes that point up

·         Flashing light: white

·         Light rhythm: quick or very quick flashes

A.   South cardinal:

·         Color: the top is yellow and the bottom is black

·         Day mark: two black conical shapes that point down

·         Flashing light: white

·         Light rhythm: 6 very quick flashes followed by a long flash every 10 sec or 6 quick flashes followed by a long flash every 15 sec

A.   East Cardinal:

·         Color: the top and the bottom are black and yellow in between

·         Day mark: two black conical shapes that point outward

·         Flashing light: white

·         Light rhythm: 3 very quick flashes (every 5 sec) or 3 quick flashes (every 10 sec)

A.   West Cardinal:

·         Color: the top and the bottom are yellow and black in between

·         Day mark: two black conical shapes that point inward

·         Flashing light: white

·         Light rhythm: 9 very quick flashes (every 10 sec) or 9 quick flashes (every 15 sec)


1.     Isolated Danger Marks

·         Color: horizontal black and red bands

·         Day mark: two black balls

·         Flashing light: white

·         Light rhythm: GP FL 2


1.     Safe Water Marks

·         Color: vertical red and white bands

·         Day mark: a red ball

·         Flashing light: white

·         Light rhythm: a long flash (every 10 sec) (LFL 10s)

1.     Special Marks

·         Color: yellow

·         Day mark: an X shape mark that looks the same from the 4 directions

·         Flashing light: yellow

·         Light rhythm: It has a distinctive sequence of various flashes that does not match any other navigational mark flashes in its vicinity.


1.     Emergency Wreck Marks

·         Color: vertical yellow and blue bands

·         Day mark: a vertical yellow painted cross

·         Flashing light: yellow and blue

·         Light rhythm: a yellow flash and a blue flash (every 3 sec)


RACON: it is an electronic devise that is used as aids to navigation mark. It is normally in a stand-by mood and would transfer the marks in form of Morse characters, which are observable on Plan Position Indicator (PPI) radar display, as soon as it receives radar pulses from a vessel.

All the aids to navigation marks along with some important specifications such as light boards, light rhythm and mark types are registered on nautical maps and are used by mariners.