Navigation Buoys And Markers Explained With Meaning - Marine Waterline (2022)

Buoys and markers serve to direct the operator of the water vessels on the safe course to take. They warn the operator of the underlying dangers in the waterways. Navigation buoys and markers are also effective navigation aid in directing the water vessel operator on the best route to use.

They aid in determining the safest way through the waters. The functions of the buoys, lights, and marks in navigation serve equivalent to those of traffic lights and road signs for drivers.

Navigation Buoys And Markers Explained With Meaning - Marine Waterline (1)

Navigation Buoys & Markers

In the navigation system, each mark features its color, shape, top mark, alongside the light. Boaters and other watercraft operators should acquaint themselves with the different meanings of each mark. By doing so, they can navigate safely to reach their destinations.

Every boater is therefore advised to carry along a navigation chart. The chart is essential in determining your location. It also serves to familiarize one with the features found in the waterway. The chart features markers, buoys, beacons, and even lighthouses.

It is essential to know that, when heading upstream, red buoys are present and are on the right side. When heading downstream, green buoys are on your left starboard, and they seem reversed.

Navigation Buoys And Markers That We Need To Know

Lateral Marks

Lateral markers are a navigation aid that serves to indicate the extent of safe water. The markers incorporate colors and numbers to pass the information.

There are different types of lateral marks; port, starboard, and even single lateral markers. Both the port and the starboard are best recognized as the lateral marks. The functionality of the different markers differs.

  • Port Hand Markers

Port hand markers feature different shapes. They are represented by red colors and also red lights. At the top, they are designed to have a can-shape. The can shape also known as a buoy. When lit, the left-hand markers display a flashing red glint of light.

Navigation Buoys And Markers Explained With Meaning - Marine Waterline (2)

Port Hand Lateral Mark

  • Starboard Hand Markers

Starboard markers feature a cone-shaped top mark. They are green in color. When lit, they exhibit a green flash of light. They are designed to have varying shapes. However, watercraft operators are advised to sail between the port and the starboard markers if they are in proximity.

Navigation Buoys And Markers Explained With Meaning - Marine Waterline (3)

Starboard Hand Lateral Mark

  • Single Lateral Marks

It is not often that you find lateral marks in pairs. Therefore, it is upon oneself to decide which side is safe to pass. The safest side through lateral navigation markers depend on; whether traveling towards or away from the sea. When sailing upstream, it denotes that you are sailing away from the sea. When one is sailing downstream, it signifies that one is traveling towards the sea.

Watercraft operators should know that, when traveling upstream, one should keep the red port hand marks on the left side. At this point, the green starboard hand marks should be on the right side. It is different when traveling downstream where the red left-hand marks should stay on the right side. In contrast to when sailing upstream, the green starboard hand mark should stay on the left-hand side on your way downstream.

(Video) How to Read Water Buoys and Markers


They feature a red color. They are cone-shaped and are marked with even numbers. They are lateral navigation aids.


They are cylindrical shaped. They feature a green color. Cans are marked with odd numbers

Cardinal Buoys

Cardinal buoys serve to give the direction of deeper waters away from water dangers. The dangers may be reefs, shallow areas, or even buoyant water surfaces. The cardinal marks give the compass direction towards the safe water. They appear painted with black and yellow colors. The cardinal buoys indicate the location of danger for each of the four cardinal points. They include;

  • North Cardinal Buoy

Its location indicates that safe waters are in the northern direction. It features a yellow coloration at the bottom and it’s black at the top. The coloring is equal for both black and yellow colors. And, they are above the waterline.

Navigation Buoys And Markers Explained With Meaning - Marine Waterline (4)

North Cardinal Buoy

It also features two cones as the top marks. The cones are black, and they lie above each other. The points face upwards. When lit, the buoy features a continuous white flash of light. But, when not lit, it remains spar shaped.

  • East Cardinal Buoy

Its location indicates that safe waters exist on the eastern side of the cardinal. It features a combination of yellow and black colors.

Navigation Buoys And Markers Explained With Meaning - Marine Waterline (5)

East Cardinal Buoy

Even so, the yellow band is broad and horizontal and usually in the middle. If it features a top mark, it is two black cones. The cones lie above each other bases. When lit, it displays a white color that flashes in a group of threes. The flashes are rapid.

  • South Cardinal Buoys

Its location indicates that the safe waters exist on the southern side of the buoy. It has an equal color of yellow and black. The coloring is above the waterline.

The upper part of the buoy is yellow whereas the lower part is black. If the buoy features a top mark, they exist as two black cones. The cones lie above each other their points pointing downwards. The buoy features a white light when lit. The light gets exhibited in groups of six which occurs very quickly. After, the lights get followed by a long flash.

  • West Cardinal Buoys

The location of the west cardinal buoys suggests that the deeper waters exist on the western side of that buoy. It features a yellow color which is separated by a broad black band.

Navigation Buoys And Markers Explained With Meaning - Marine Waterline (7)

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West Cardinal Buoy

Its top mark features two cones that lie above each other. The cones’ points face each other. When lit, the buoy exhibits a white color which flashes in a group of nine. The flashes are rapid. If in any case, the buoy has no light, it is spar-shaped.

Isolated Danger Mark Buoys

The buoy indicates the presence of danger such as rocks and shoals. The waters around the buoy are navigable only when the vessel does not get too close. The buoy is black, featuring one or more horizontal red bands. At the top, they have two black spheres.

Navigation Buoys And Markers Explained With Meaning - Marine Waterline (8)

Isolated Danger Mark

When lit, the buoy exhibits white flashes of light in groups of two.

Safe Water Marks

Safe water marks indicate the existence of navigable waters all around the buoy. The buoy has red and white vertical stripes. The top mark features a red sphere.

Navigation Buoys And Markers Explained With Meaning - Marine Waterline (9)

Safe Water Mark

When lit, the buoy exhibits a white flash of light that lasts for about ten seconds. And, after every ten seconds, the flash is on again.

Special Mark buoys

The buoy serves to indicate the presence of special features. Such a feature may be pipelines or cables. They can also indicate the presence of a channel within a channel.

Navigation Buoys And Markers Explained With Meaning - Marine Waterline (10)

Special Mark Buoy

The way out through such special features is indicated in the boating charts. The buoy features a yellow color, and an X indicates the top mark. When lit at night, the buoy exhibits a yellow flash of light.

Emergency Wreck Marking Buoy

They are useful in indicating new dangers and wreckage. They feature some vertical blue and yellow stripes. The top mark is a yellow cross.

Navigation Buoys And Markers Explained With Meaning - Marine Waterline (11)

Emergency Wreck Marking Buoy

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They are designed to have either a spar or a pillar shape. When lit, the flash of blue and yellow light alternates in a span of about one minute. Before another light flash, a moment of about half a second gets marked with darkness.

Non-Lateral Markers (Information And Regulatory)

They inform the watercraft operators about another topic alongside an area of safe waters. Commonly used are the regulatory markers. The markers are white and utilize orange markings and black lettering. They include;

  • Squares (Information)

They deliver information about where to find food, supplies, or even repairs. They also give information about the direction.

Navigation Buoys And Markers Explained With Meaning - Marine Waterline (12)

Regulatory Markers

  • Restricted Operations Mark

This mark with a circle means that only regulated operations are permitted in this zone.

  • Danger

A white buoy with orange bands at the top and bottom. In the middle with the diamond means danger. Usually, the danger is lettered.

  • Exclusion

A cross inside the diamond signifies that boats can not enter that area.

  • Diving Buoy

It serves to mark an area where activities such as scuba are taking place. The buoy features a white color with a red flag of above fifty centimeters square. The flag has a white diagonal stripe. When lit, the buoy exhibits a yellow flash of light

Navigation Buoys And Markers Explained With Meaning - Marine Waterline (13)

Diving Buoy

  • Mooring Buoys

They serve to indicate the anchoring zone. They are white, featuring a blue horizontal band. Mostly, they are found in marinas.

It’s important to know where we can anchor. Also, we must know where we should avoid anchoring.

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Mooring Buoys

  • Inland waters Obstruction Markers

White and black vertical stripes are the colors of these buoys. It indicates an obstruction to the navigation. We should not go between these marks and the closest shore.

Navigation Buoys And Markers Explained With Meaning - Marine Waterline (15)

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Inland Waters Obstruction Mark

Intercoastal Waterway Marks (ICW)

These yellow squares and triangles are used to mark other waters. ICW marks are found from New Jersey To the Mexican border. Yellow triangles should be kept on the starboard side (right) of the vessel and the yellow squares should be kept on the port (left) side of the vessel.

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Intercoastal Waterway Markers

A yellow horizontal band does not provide any lateral information but, marks the ICW.

Leads and Sector Lights

Leads serve to guide water vessels through the waterway. Not only navigation buoys and markers but also the leads are navigation aids through the water. When in the waterway, your vessel should always remain on the safe course.

When it is dark, one should ensure that all the red white, and green lights are vertically aligned with each other. The boaters’ charts and maps have leads. Thus, they are easy to identify.

The chart will help one familiarize himself with the leads before he or she enters an insecure waterway.

Even though, sector light varies from one to the other. When present with a red sector light, one should turn to starboard. If the color is green, one should turn to port.

But, the white color sector light indicates that it is safe to take the course. In some sectors, the lights may mark the entrance to the port. Therefore, it is wise to know that the white sector is the shipping way to the sea.

Blue Middle Channel Mark

These are fixed blue lights. They indicate the middle of a channel. The buoy is useful for a vessel passing below a bridge to maintain its track. However, on boating charts, the blue middle channel marks appear as a star. The star gets symbolized with a flash.

Speed Signs

Speed signs are installed in the waterway to ensure safety. When sailing, the watercraft operator should ensure that he or she travels within a limited speed.

Otherwise, exceeding the speed incurs penalties. Mostly, the speed restrictions are between Four knots and fifteen knots. Every speed determines the kilometers to travel with the speed.

Navigation Through Channels and Rivers

A channel is taken to mean a place whereby it is safe to navigate through. Some channels, though navigable, are not marked. When navigating through channels, it is advisable that one keeps to starboard. Normally, a channel can get too narrow, and thus, it is a must that the sailor keeps to starboard.

However, when sailing along estuaries and rivers, watercraft operators are advised to be super cautious. The reason is that; it is not always that the shallow and navigation hazard zones get marked with the buoys and markers. Even when marked, the shallow area may shift position.

When negotiating bends, extra caution is required. One should look out for oncoming boats to avoid accidents. It is also advisable not to cut corners.

Similarly, in channels and other shallow water stretches, rules and regulations for safety still abide. Forever, it is safe to keep to the starboard which is the right-hand side.

One should be cautious not to impede the passage of large vessels. Water alterations may result to change of the course. Thus, one should be well informed about the channel.

Fishing in channels can obstruct other watercraft from the easy passage. It is therefore right not to go fishing in narrow channels.


The watercraft operator should ensure that the wash they create does not impact negatively on life in the water or constructions in progress. Different sites get placed with no wash sign. Thus, the vessel operators should ensure that they abide by the rules.

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It is wise to be cautious and look behind to see whether your vessel is creating any wash. The excess wash may endanger other vessels and also destroy plants in the water. It is fair enough to adjust to the necessary speed that is wash free.


It is upon all watercraft holders to know their way through the waters. One should get acquainted with every sign and symbol and still know their meaning. By doing so, boating safety is enhanced.

If we find the navigation aids or buoys and markers are not in good condition or not used in the right place, we must inform the nearest US Coast Guard unit.

This is your COMPLETE boating buoy guide. Save it to your phone for easy navigating when on your boat. All the buoys and markers you need to know.

But how do you know where to go when you’re in a boat?. Boat buoys and markers, that’s how.. There are also some other letters and numbers in black, off to one side of the marker location on the map.. That way, if you are out on a boat on the water, you can identify the major lighted marker by the way it looks and then corresponds that to the information on your navigation system or map.. This is how the range markers would look from a boat when in line with the pair of markers.. Sometimes this buoy has a light, and when this is the case, the light will be green in color.. This topmark is seen from all directions along the horizontal as a square from a distance.. When equipped with a light, the light will flash a red sequence, as noted on the above graphic.. The buoy will sometimes have a light, and if it does, the light will flash yellow in the described sequence.. No topmark is used on control buoys, but sometimes they do have a light that flashes in yellow with the same sequence as many other special buoys.. The Mooring Buoy is typically white with an orange cap on the top.. This buoy usually also has a topmark in the shape of a sphere; and white rather than the orange of the top of the buoy.. You have likely seen these buoys before.

It's very important that every boating enthusiast be aware of the visual boating distress signals. US distress signals coast guard approved

It’s very important that every boating enthusiast be aware of the visual boating distress signals to be used in the event of an emergency, or that might indicate that a nearby boat is in trouble.. Here are the most important boating distress signals to know, when they’re appropriate for use, and what you should do if you see them out on the water.. The accepted US distress signals are listed in the Coast Guard’s Navigation rule 37, which states that boats shall use accepted distress signals to communicate to others that they require assistance.. In the event of an emergency, you’ll likely need to set off more than one flare to catch the attention of another boat.. There are a variety of other types of distress signals that can be used to indicate an emergency.. Communicating your distress via radio or morse code is another way to indicate to nearby boats that you need help.. Of course, in many cases, you may not be able to send out a radio signal, but if you can, this is one of the first things you should do.. It should be far enough out of the way that others won’t accidentally move them or open them, but they should still be easy to reach in the event of an emergency.. It’s important to be very cautious when setting off pyrotechnic distress signals because they can be very dangerous if not used correctly.. In these cases, audio distress signals such as a foghorn or a radio signal will be much more effective.. It’s important to be prepared to help if you see another boat in distress.

One of the most confusing aspects of the entire marine world is the system of marks, buoys, lights and shapes that decorate the seascape.

The USA, North and South America, Japan, the Carribean, the Philippines and Korea all operate under the IALA B system of lights and aids to navigation where even numbers on red buoys are kept on the right when returning from sea.. The rest of the world operates under the IALA A system where it is nearly opposite of IALA B, where odd numbers on green buoys are kept on the right when returning from sea.. Prior to the 1970’s the green buoys were once black buoys, but to adhere to the International system of maritime colors and match what half of the Country was doing at that time, the USCG standardized signification of the right and left sides of the channels everywhere by putting even red nuns on the right hand side of the channel when returning from sea.. On the other side we have Odd Green Cans or green buoys with odd numbers and they are shaped like a can or cylinder.. As you travel up from sea, the right hand side of a channel, harbor, bay or river will have the number “2” on the first red nun buoy and increase with even numbers as you progress up from sea on similarly shaped and colored buoys.. On the left hand side, your first buoys will be green and can-shaped and they will start at the number 1 and progress up from sea with odd numbers on similarly colored and shaped buoys.. The last mark we need to discuss under the Lateral Section of buoys is the Mid Channel Marks or Preferred Channel buoys.. These are half red and half green marks that are displayed with letters instead of numbers where a channel splits and indicates which side of the split is preferred.. If you're still with me and even if you're not, the US government has given us a system of keys to deduce what all these buoys mean and charts to help us find and identify where all these buoys might be located.. The red and green buoys make up the lion's share of buoys you might see on the water , aka the Lateral system.. They are called the Non-Lateral system because unlike the red and green buoys that make up lines where your boat should and should not go, non-lateral buoys are placed to identify places outside those lines where you really need to know where you are.. Other buoys of note under IALA A include the directional buoys or Cardinal marks and you will find them in relation to the prescribed path regardless of the position of the vessel.. One of the most confusing aspects of the entire marine world is the system of marks, buoys, lights and shapes that decorate the seascape.

Queensland uses an internationally recognised uniform coding system of navigation marks known as the International Association of Lighthouse Authorities (IALA) buoyage system 'A'. This system uses 5 different types of marks to distinguish safe navigation.

Lateral marks show the port (left) and starboard (right) sides of navigable waters or channels.. At night, a port buoy shows. a red flashing light (when lit).. When a port and starboard lateral mark are opposite each other, travel between them.. When there is a single lateral mark, the safe side to pass depends on the direction of travel (or buoyage).The direction of buoyage is shown on charts by the symbol:. They can mark:. Cardinal marks have black and yellow bands with black double cones on top showing the different compass direction that identifies the safest and deepest water to travel in.. Safe water marks Safe water marks show that there is navigable water all around the mark.. To remember safe water marks, think of 1 light with 1 long flash and 1 sphere for the top mark.. The direction to travel around a special mark is usually referred to or shown on charts.. At night, the flashing light is yellow.. When the leads are in line, you are travelling in the middle of the channel.

A guide to the navigation aids we really need to know and what their chart symbols look like on the water

Regardless of which system you use, there are six types of navigational marks – cardinal, isolated danger, emergency wreck, safe water, lateral and special.. When we come off passage, the first mark we come across is the safe water mark, also known as a fairway buoy.. The port hand mark pictured below has a green strip around its middle, telling us we can go to port of it (which would see us travelling left to right past the far side of pontoon B1), but the preferred channel is to starboard.. If lit, the light will be yellow and usually a rhythm of FL.Y (flashing yellow) or FL.Y4s (flashing yellow once every 4s). Cardinal marks There are three types of danger marks – cardinal marks, isolated danger marks and emergency wreck marking buoys.. Named after the four cardinal points of the compass, cardinal marks tell you where safe water is.. It’s important to be able to identify a cardinal either by its topmark or by its colour, but bear in mind top marks can go missing and often cardinals become faded or indistinct in colour.. As to colour, the yoke in the middle of the egg is yellow, similar to the colour of the cardinal – yellow in the middle with black above and below.. As before, if the cones always point to black, then the cones on a west cardinal pointing inwards correspond to the black band in the middle of the two yellows.. Later, if the wreck is not cleared away, it will either be allocated cardinal marks or an isolated danger mark.. A wreck marking buoy carries blue and yellow stripes, with a cross for the top mark.. It has a top mark of two black balls, while the post is coloured black with one or more horizontal red bands.. These marks are shown on the chart with the two balls for the top mark and underneath BRB for the colour of the post. Red lights will be marked R, green lights G, yellow lights Y and blue lights Bu.. The post of this cardinal is so covered in guano that we have no idea of its colour, while below, the cardinal’s top mark is missing.

It is very important that all boat owners fully understand what the different navigational lights on their boat mean, and how to properly obey the laws

It is your responsibility to make sure that your boat has the proper navigation lighting configuration before you head out on the water.. Motorized vessels Non-motorized vessels Sailing vessels (Operating under sails) Sailing vessels (Operating under motor power) Vessels engaged in fishing Vessels engaged in trawling Towing vessels Anchored vessels Human-powered vessels such as Rowboats (Kayaks and canoes). Boats are required to have navigation lights.. The type of lights required depends on the length of your vessel as well as if it’s a powered or non-powered vessel.. A red sidelight indicates the port side of the vessel, while a green light shows the starboard side of the vessel.. A white masthead light located at the front of the boat, pointing in the direction you are traveling.. You are required to display a white light that can be seen by other boats.. White all-around light is required to be used so you are visible to other ships that could be in the area.. Contact information can be found here: .. For example, if you are sailing towards another vessel, you will be able to tell if that vessel is heading towards you, or if it is heading away from you based on which side the green and red lights appear to you.. If you see a green light from an oncoming vessel than you would know that it’s on your left, which means you have the right of way.. It is your responsibility to ensure that your boat has all of the proper equipment for your safety and the safety of others.. All-Round Light: White (32pt/ 360°) Masthead Light: White (20pt/ 225°) Sidelights: Red (10pt/ 112.5°) & Green (10pt/ 112.5°) Stern Light: White (12pt/ 135°)

Port of Milford Haven

are red the basic shape is cylindrical (sometimes with a topmark) if lit, the light will be red and have a specific flash sequence (this will be shown on the corresponding chart to help you identify your location) should be on the port (left) side of your vessel when travelling in the direction of buoyage (upriver).. green (exceptionally, black may be used) the basic shape is conical (sometimes with a topmark) if lit, the light will be green and have a specific flash sequence (this will be shown on the corresponding chart to help you identify your location) should be on the starboard (right) side of your vessel when travelling in the direction of buoyage (upriver).. During daylight the most important feature of the cardinal mark is the black double cone topmark and the four different arrangements that indicate the relevant direction of safe water from the mark.. The black and yellow horizontal bands used to colour the cardinal marks also indicates where safe water lies in relation to the mark.. At night cardinal marks are lit with a flashing white light.. If lit, the light (white) will show as two flashes.. These are used to indicate that there is navigable water all around the mark, or to indicate the start of a buoyed channel with port and starboard lateral marks.. Surface marker buoys can take many shapes.. While the ‘A’ flag is most commonly used by dive vessels, a red flag with diagonal white strip (shown right) is also an internationally recognised flag to indicate that divers are in the water.. Lights and shapes are also used by vessels to communicate.. Needs to display a single white all round light.. Needs to show a white masthead light, a white stern light and port and starboard lights.. Vessels under 50 metres need to show a single all round white light, while vessels over 50 metres should display two white lights, with the stern one lower than the bow.. Dive boats should show a code flag (as outlined in the flags section).. These show the usual lights for a powered vessel with the addition of an all round red light above its white light.

Chapter VI - Operations Section 3 - Aids To Navigation Aids To Navigation In order to find our way safely from place to place on the water we must depend on road signs just as we do on land. The aids to navigation are the road signs of the water.…

To navigate safely using the lateral markers, you should pass between the red and green.. Lateral Buoys and waterway markers. In the International system, navigation aids mark the edges of channels to tell which way open water is.. If you are returning from sea and see a preferred channel marker that is red over green, to stay in the main channel you would consider the marker as if it were a red marker and keep it on your right.. The first marker you see entering from sea is the open, or safe water, marker.. R N “2” plus the red symbol indicates a R ed N un buoy with the even number 2 on it.. Otherwise, the colors and numbering of buoys and day marks, and lights follow the same system as that observed in all other waterways.. Aids to navigation marking the Intracoastal Waterway (ICW) display unique yellow symbols to distinguish them from aids marking other waters.. Lighted green ” Can Buoy “, port side channel marker returning from the sea.


1. Ep 39: Understanding Navigational Aids
(Carpe Diem Sailing)
2. Lateral Buoys Explained { NEW TRICKS }
(NAUTICAL Studios)
3. Understanding Marine Buoyage - "quieter volume" - simple and easy
(Coastal Safety)
4. Boating Tips Episode 8: Understanding Channel Markers
5. Which Side of the Beacon?
6. what is the area between a red and green buoy

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