Red Right Returning: Reading Buoys and Markers

The water looks open and empty, but a navigable channel is marked as clearly as a highway once you learn to read the signs. Buoys and markers form a system that tells you where the deep water is, which side to pass on, and what hazards lie ahead. Learn the basics and a busy harbor stops feeling like a puzzle and starts feeling like a route.

Red, Green, and the Phrase That Saves You

The two colors you will see most are red and green, and they mark the edges of a channel. In the system used across North and South America, the memory trick is "red right returning": when you are returning from open water toward a harbor or heading upstream, keep the red markers on your right side and the green markers on your left.

Red markers are usually triangular and carry even numbers. Green markers are square and carry odd numbers. The numbers generally increase as you head upstream, which gives you a rough sense of progress along the channel. Reverse the whole picture when you head back out to sea: the red markers move to your left, the green to your right.

Cans, Nuns, and Daymarks

Floating markers come in shapes with old, useful names. A "nun" is a red buoy that tapers to a point on top. A "can" is a green buoy with a flat cylindrical top. Fixed markers mounted on posts are called daymarks, and they follow the same color and shape logic. Learning the shapes matters at dawn or dusk, when colors are hard to judge but a silhouette still reads clearly against the sky.

Safe Water and Hazard Markers

Not every marker defines a channel edge. Red-and-white vertically striped markers indicate safe water all around, often marking a channel entrance or the middle of a fairway. Markers with horizontal bands warn of an isolated hazard, such as a rock or wreck, and you keep well clear of them on all sides. When you see something unfamiliar, the safest response is to slow down, keep clear, and check your chart before committing to a course.

Lights After Dark

Many markers carry lights for night navigation, and the colors match the daytime marks: red lights on red markers, green on green. The lights also flash in distinct rhythms so you can tell one marker from another. A chart lists each light's color and pattern, which is why night navigation always pairs what you see on the water with what the chart promises you will find.

Reading a Chart Before You Cast Off

The markers make sense only against a chart, so spend a few minutes with one before you leave the dock. Trace the route you plan to sail and note which markers you expect, in what order, and on which side each should pass. A chart also shows depths, so you can see where the water shoals and stay in the comfortable middle of the channel rather than wandering toward the edges.

Trust the Chart, Confirm with Your Eyes

Markers can drift, tilt, or go dark, so treat them as confirmation rather than absolute truth. On the water, match each marker to the chart as you pass it. That habit, more than any single rule, is what keeps a relaxed skipper out of trouble. It turns a confusing shoreline into a road you can follow with quiet confidence, day or night.

It also pays to know the local quirks before you go. Some harbors have a marked channel that doglegs sharply, and a beginner who assumes a straight line between two buoys can find the bottom in a hurry. Ask a local sailor or the harbormaster which way the deep water runs, and note any spots where the markers are widely spaced. The system is consistent, but the water underneath it is not, and the sailors who never run aground are simply the ones who look ahead, go slowly in unfamiliar places, and never assume the gap between two marks is automatically safe.