Buoys are floating, anchored aids to marine navigation. A buoy today may come in many shapes, sizes, and colors. These different shapes and colors indicate a specific meaning or a specific type of buoy. Understanding the different types of buoys will allow you, as a boat operator, to navigate safely and efficiently on the water.

Buoys can indicate the location of hazards in the water, safe places to moor your vessels, channels that can and can’t be navigated, and more.

Types of Buoys

There are several common types of buoys that you will find on the water. These include

  • Lateral buoys – Includes port hand buoys, starboard hand buoys, and bifurcation buoys. These buoys are always red or green. Green marks port and red marks starboard. This system applies to the Americas, Japan, South Korea, and the Philippines. The rest of the nautical world reverses this with red buoys to port and green buoys starboard. You can read more about lateral buoys in our article.
  • Cardinal buoys – These mark the cardinal directions and show the direction of safe water. They will always be black and yellow.
  • Isolated danger buoys – These mark specific dangers like reefs, rocks, or even shipwrecks so boaters know to navigate around them safely. They will be black with red bands.
  • Navigation buoys – A navigational buoy could include safe water buoys, isolated danger buoys, a channel marker buoy, and various special buoys. The color and design will change based on the buoy. For instance, a safe water buoy is usually red with white vertical stripes.
  • Information buoys – these include weather buoys. Information buoys will be white, featuring an orange square on two sides and an orange band above and below the square.
  • Mooring buoys – Moored buoys and firmly anchored buoys to which you can tie your boat. These are white with an orange stripe.
  • Special buoys – These can range from diving buoys to hazard markers and more. Sometimes these are regional buoys that don’t always follow international standards and are, therefore harder to understand. The colors and markings may not always be familiar to you if you’re not local and are used to seeing them. A special buoy is typically yellow and often marked with an X, but not always.

Among the many major types of buoys are various subtypes. For instance, race course navigation buoys are deployed for yacht racing. Emergency wreck buoys are used to mark a very recent wreck within the first day or two of its sinking to alert boaters to the new danger in the water. Lobster trap buoys are temporary buoys that will indicate where lobster fishermen have dropped a trap so that it can be pulled up later. Dive buoys show where divers have gone down to mark their positions. These are just a few of the many potential buoys that may be seen on the water.

History of Buoys

The earliest known written reference to buoys comes from a book called La Compasso de Navigare that dates back to 1295. This mariner’s handbook was from Spain and detailed how to navigate the Iberian peninsula safely. The book marked the location of a buoy on one of its charts. It would have been a simple wooden raft moored in place at that time. Its purpose was to help direct boats to and from Sevilla.

By the mid-1300s, buoys were hollow drums or barrels held in place by chains attached to heavy rocks. By the end of the 1500s, as many as 40 buoys were deployed in the Zuider Zee, a bay in the North Sea in the Netherlands. About 30 could be found throughout the rivers of Northern Germany, and England had a handful as well.

In the early days of America, cask buoys were still popular, as were what is known as a spar buoy. This was just a large pole hammered into a riverbed or sea floor to mark the position permanently.

Buoys remained mostly the same for centuries until the development of simple bell buoys that could also aid mariners at night by offering sound signals. Before this, a buoy was only useful during the day.

Buoys with whistles and then lights soon followed, making them invaluable aids for navigation not just during the day but at night and in storms when all boaters could more easily detect them.

In the 1800s, the lateral buoy system was adopted. This was when red starboard buoys first appeared, and black port buoys were used. In time, black was replaced with green as it was easier to see these bright-colored buoys at a greater distance. The two colors remain today, but, as we have mentioned, the colors are reversed in some parts of the world.

Different Buoy Systems

For a time in the United States, there was confusion between more than one system of navigational aids. We used the Uniform State Waterway Marking System (USWMS) and the United States Aids to Navigation System (USATONS). These systems, while similar, also had several confusing differences. However, in 1998, the Coast Guard began its five-year plan to merge the systems, which took final effect in 2003.

As mentioned above, much of the rest of the world still uses a different system for lateral buoys, the most significant of which is that they reverse the red and green port and starboard buoys compared to what we do in the US. It’s imperative to understand all the maritime rules in international waters. You can never count on this being consistent from one country to the next.

Accessing Helpful Buoy Information

Depending on the buoy in question, you can get a lot of potential information from them. For instance, check out the NOAA’s National Data Buoy Center. This service provides you with a map of weather buoys across the globe. You can use this to give you recent information about the weather anywhere you may be boating soon.

Importance of Buoys

Regardless of the type of buoy, you can think of them like road signs for driving. They indicate in which direction traffic should flow, where hazards are and how to avoid them, and the safest routes. Without buoys, there would be considerably more accidents on the water, especially close to harbors and mariners with heavy traffic. Imagine rush hour traffic on roads with no stop signs, no lines to show lanes, and no speed limits. It would be chaos.

Buoys can also provide vital information on water conditions, weather, hazards, and more that can be transmitted in real-time to monitoring stations and dispersed to improve safety for all boaters, including those who haven’t yet gotten on the water. Information buoys that transmit data about worsening sea conditions can help prevent new boaters from getting on the water ahead of a storm, for instance.

Buoys are vital in life-saving rescue work at sea as well. They can be used as reference points for search and rescue work. In addition, a buoy deployed at the location of a disaster, such as a man overboard situation, can greatly aid in rescue.

The Bottom Line

What is a buoy? A buoy is a floating object anchored in the water that aids marine navigation is the simplest answer. They may come in many shapes and sizes depending on what the buoy is being used for. Understanding the basic navigational buoys is essential for safe boating practices.

Buoys are used to show the safest paths to follow, the location of various hazards, where you can safely moor a vessel, and much more. Modern data buoys can transmit important, up-to-date information about sea conditions that you can monitor worldwide.