Marinetalk is supported by its audience. When you purchase through links on our site, we may earn an affiliate commission. Learn more

What Color Are Safe Water Markers? How to Spot Them?

Fact checked by William Hart

what color are safe water markers

The U.S. Coast Guard owns and maintains approximately 36,000 aids for navigation on the open sea, which sounds overwhelming for new boaters.

Don’t get discouraged, though!

All navigation markers follow a logical and straightforward system.

To recognize a marker on the water, you just need to learn its colors, shapes, lights, and nautical chart symbols. So, what color are safe water markers?

They stand out with red vertical stripes on a white background. They might also bear red topmarks in sphere shapes. During the nighttime, you must notify them by their lights, which flash Morse code A.

Below, you will find more characteristics of this marker. Keep reading to learn how you can spot one at a glance.

Table of Contents

What Do Safe Water Markers Look Like?


As the name implies, these aids indicate safe water. They mark fairways, mid-channels, and other offshore points that are safe to pass on all sides. Boaters might call them fairway buoys or safe water buoys. They have:

1. White and red vertical stripes

The safe water markers’ color is white and red portrayed in vertical stripes. You can pass them on all sides. But if a fairway buoy is in the middle of a channel (check this information on your nautical chart), you should keep it to your port (left) side.

2. A variety of shapes

These buoys can have the shape of a sphere, pillar, or spar.

3. Letters

Some safe water buoys carry a letter on both sides; some don’t. The letter is the name of the buoy.

You can check if the name on your nautical chart is similar to the letter on it to ensure you reach the correct marker.

4. Red topmark

Most safe water aids have a red sphere on top so boaters can see them easily.

5. Lights

These markers might be lighted or unlighted. If a safe water buoy is lighted, it displays Morse code A (di-dah), which is a three-second flash followed by a one-second flash.

At night, you can only identify an aid to navigation by its light characteristic. Keep this lighting information in mind for safe water markers boating.

How to Interpret a Safe Water Marker Symbol on the Nautical Chart


Reading nautical charts is a crucial boating skill. You can’t navigate the water when you don’t know what lies ahead.

On the chart, a white marker with red vertical stripes might carry a diamond or square symbol. The symbol comes with letters on its right side. Here’s how to read the symbols:

  • The first letters indicate the color of the buoy. All safe water markers start with a capitalized RW (red and white).
  • The following letter shows the name of the buoy inside quotation marks. Safe water markers are usually named “A”, “G”, or “N”.
  • If the symbol above the letters has a red round shape at the bottom, that buoy carries a red topmark.
  • You will find the buoy’s light and sound characteristics underneath. This information is written straightforwardly, such as unlighted with or w/o sound and lighted with or w/o sound.

For example, if the electronic chart system shows that your boat is approaching a safe water marker symbol followed by RW “N” Mo (A), you can tell your sailing crew to keep an eye for a red and white buoy named N that flashes Morse code A. When the buoy is in sight, the crew members give signals so you can maneuver the boat accordingly.

Every small boat owner must learn to read nautical charts. Besides spotting the marker in the chart, you must interpret it quickly and properly so your sailing crew can look for the correct marker on the water. Communicating effectively ensures safe trips.

Why Do Safe Water Markers Carry Red Stripes on a White Background?


Now, you know what color marker indicates safe water, but why is it painted like so? What is the meaning behind these red and white stripes?

On land, we often see signs with alternating red and white stripes that indicate danger. It is because red on a white background pulls attention. Such signs are also more visible during low light.

The same idea applies to the buoy system. IALA (The International Association of Marine Aids to Navigation and Lighthouse Authorities) choose red and white because they stand out in nature, allowing boaters to spot them from afar.

Fairway buoys are just one type of marker used to warn boaters. Many other types of buoys use stripes, too. Danger water buoys have red stripes on a black background, while obstruction buoys have black stripes on a white background.

Safety Precautions


When you approach a fairway buoy:

  • Don’t assume the position or meaning of a marker. You must consult the nautical chart to determine the exact information.
  • Don’t rely solely on one aid of navigation to determine your position as natural causes might shift them away from their original spot.
  • Many hazardous areas are not marked. When you navigate unknown water, always proceed with caution. Never assume an area is safe because there are no warning buoys.
  • You should use an updated nautical chart and check for any important notices before a boating trip.
  • You should keep a safe distance when approaching an aid of navigation to avoid a collision.


To conclude, the answer to “What color are safe water markers?” is red vertical stripes against a white background. To quickly distinguish them from a mooring or red buoy (channel marker), remember that they may have:

  • A pillar, spherical, or spar shape
  • One letter on both sides
  • A red sphere topmark
  • Lights displaying Morse code A

The U.S. Coast Guard has numerous buoys and aids for navigation. Once you understand safe water markers, read further on our website to learn more about other types. Before you leave, feel free to leave us your questions in the comment section. See you out on the water!

5/5 - (2 votes)