US Buoyage (IALA B)

Prerequisites

• The basics of reading a chart and its symbols.
• Knowing port and starboard, and what "returning from seaward" means.
• If you learned IALA Region A buoyage first (red to port coming in), this lesson shows what changes in Region B.

Learning Objectives

This lesson covers the aids to navigation section of the ASA 101 Keelboat Sailing 1 standard. By the end of it you will be able to:

• Explain the difference between IALA Region A and Region B, and say where each is used.
• Identify US lateral marks by colour, shape, number and light, and apply "red right returning".
• Identify preferred-channel, safe water, isolated danger, cardinal and special marks.
• Read the light characteristics printed beside a mark on a chart.
• Use ranges (leading lines) and the Intracoastal Waterway markings.
• Avoid the mistakes that put boats aground in unfamiliar channels.

Why Buoyage Differs Around the World

Until 1977 there were about 30 different buoyage systems in use. The International Association of Lighthouse Authorities (IALA) reduced them to two:

• Region A: Europe, Africa, Australia, New Zealand, India and most of Asia. Red marks are on the port side when entering from sea.
• Region B: North, Central and South America, Japan, South Korea and the Philippines. Red marks are on the starboard side when entering from sea.

Lateral marks are the only marks that differ between the two regions. Cardinal, isolated danger, safe water and special marks look the same everywhere. If you charter abroad, check which region you are in before you leave the dock.

The Direction of Buoyage

Lateral marks are laid out for a boat returning from seaward: entering a harbour, going up a river or heading towards the head of navigation. Along a coast, the conventional direction in US waters runs clockwise around the continent: south along the Atlantic coast, west along the Gulf coast, and north along the Pacific coast. On the Great Lakes it generally runs westward and northward. Where the direction is not obvious, the chart shows it with a magenta arrow symbol.

When you are heading out to sea, everything is reversed: red is on your port side.

Lateral Marks: Red Right Returning

The mnemonic is "Red, Right, Returning": when returning from sea, keep red marks on your right (starboard) side.

Memory aids:

• Even red nun: red marks carry even numbers and are nuns.
• Odd green can.
• Numbers increase as you travel in from seaward, so a rising number tells you that you are heading in.
• A lighted buoy may be a pillar or spar instead of a nun or can. In that case identify it by its colour, number and light.

Daybeacons are fixed structures (piles or posts) carrying a dayboard. Treat them exactly like the floating buoy of the same colour. Because they stand on the bottom, they are usually right at the edge of the shallows. Pass them with a margin.

Preferred-Channel Marks

Where a channel divides, a preferred-channel (junction) mark shows which branch is the main one. It has horizontal red and green bands. The colour of the top band tells you which way to treat it for the preferred channel:

• Red top band: treat it like a red mark. Keep it to starboard when returning, and the preferred channel is to its left.
• Green top band: treat it like a green mark. Keep it to port when returning, and the preferred channel is to its right.

Its light, if fitted, is the colour of the top band and flashes in the composite group Fl(2+1). Preferred-channel marks carry letters, not numbers.

Non-Lateral Marks (the Same Worldwide)

Safe water mark

• Red and white vertical stripes, sphere-shaped or with a red spherical topmark.
• White light, Morse A (Mo(A)), isophase, occulting or long flash.
• Marks the fairway or mid-channel and the landfall buoy outside a harbour. There is navigable water all around. Pass close to it, normally keeping it to port.

Isolated danger mark

• Black with one or more broad red horizontal bands, and two black spheres as a topmark.
• White light, group flashing (2).
• Sits directly over a small danger with navigable water all around. Give it a wide berth.

Cardinal marks

Cardinal marks are rare in the US but are used in some places, and you will meet them when chartering abroad. They show on which side of a danger the safe water lies: pass north of a north cardinal, and so on. They are black and yellow, with two black cone topmarks, and show quick or very quick white lights. To remember the number of flashes, use a clock face: north continuous, east 3, south 6 plus a long flash, and west 9.

Special marks

• Yellow, with a yellow X topmark if one is fitted.
• Yellow light, any rhythm not used by the white marks.
• They mark something special rather than a channel side: anchorages, cable areas, spoil grounds, traffic separation, or the Intracoastal Waterway.

Emergency wreck marking buoy

This mark is blue and yellow, with a yellow upright cross topmark and an alternating blue and yellow light. It marks a new wreck that is not yet on the charts. Give it a wide berth.

US Information and Regulatory Marks

These are white, with orange shapes. They are used on inland and coastal waters:

• Orange diamond: danger, such as rocks, a wreck or a dam.
• Orange diamond with a cross inside: boats keep out, for example a swimming area or a dam.
• Orange circle: controlled area, such as no wake, a speed limit or no anchoring. The rule is written inside the circle.
• Orange square or rectangle: information, such as directions, distances or the location of fuel.

A white buoy with a blue horizontal band is a mooring buoy.

Intracoastal Waterway (ICW) Markings

The ICW runs along the Atlantic and Gulf coasts. Its marks carry an extra yellow symbol that shows how to treat the mark when travelling along the ICW. The conventional ICW direction is from New Jersey towards Texas, which roughly counts as "returning".

• Yellow triangle: keep the mark on your starboard side when going along the ICW from New Jersey towards Texas. It applies whatever the colour of the mark.
• Yellow square: keep the mark on your port side when going along the ICW from New Jersey towards Texas.
• Yellow horizontal band: no lateral meaning. It just tells you that the mark is part of the ICW.

Where the ICW shares a channel that leads in from the sea, a mark may be red with a yellow square. Follow the colour of the mark for the inbound channel, and the yellow symbol for the ICW.

Reading Lights on the Chart

The text beside a lit mark gives its colour, rhythm and period, then sometimes its height and range:

• Fl G 4s: one green flash every 4 seconds.
• Q R: quick flashing red, 50 to 79 flashes per minute. Quick flashes mark a point that needs particular care, such as a sharp turn.
• Fl(2+1) R 6s: a red-topped preferred-channel mark.
• Mo(A) W: a safe water mark. Its pattern is short-long.
• Iso 6s: equal periods of light and darkness, 6 seconds per cycle.
• Oc: occulting, which means the light is on longer than it is off.
• If no colour is given, the light is white.

Other details on the chart:

• "Bell", "Gong", "Whis" or "Horn" next to a buoy means it makes a sound. Bells and gongs are worked by wave motion, so they may be silent in calm water.
• "Ra Ref" means the mark has a radar reflector. "Racon" means it returns a coded signal on radar.
• Lit buoys can rarely be seen beyond about 3 miles. Often the range is under 1 mile in the glare of shore lights.

To identify a light, time it with a watch through two or three full cycles. Compare it with the chart and expect to see it on the bearing you predicted.

Ranges (Leading Lines)

A range is a pair of fixed marks, the front one lower and the rear one higher and further away. When you see them in line, one above the other, you are on the centre line of the channel. The range boards usually have vertical stripes, and the lights are often the same colour.

• If the rear mark appears to the right of the front mark, you are to the left of the line. Steer right to bring them back into line.
• If the rear mark appears to the left of the front mark, steer left.
• On the chart, a solid line shows the part of the range that is a safe track. A dashed part runs over land or shoal water, where you must not follow it.
• Only follow a range as far as the chart says. A channel often turns before you reach the front mark.

Seamanship with Buoys

• Buoys move. They drag in storms, swing on long chains and can be off station. Use them as guides, not as exact fixes, and check against other references.
• Do not cut close to marks. A buoy marks a channel edge, and its chain sweeps a circle around it.
• Keep a logical count. If you have just passed "6" and the next one you see is "10", look for "8" before turning.
• Watch the tide around a buoy. The water heaps up on the up-tide side, and a wake streams down-tide. This shows the set of the current.
• At night, have the chart and a list of the expected lights ready before entering, and keep a red light on in the cockpit to preserve night vision.
• Never tie up to a navigation mark. It is illegal in US waters and blocks the mark for other boats.

Worked Example: Entering a Harbour at Dusk

You approach a harbour from the sea. The chart shows a red and white Mo(A) whistle buoy "SC" outside, then green "1" (Fl G 4s), red "2" (Fl R 4s), and a junction buoy "B" (red over green, Fl(2+1) R 6s), where a secondary channel branches off to the right.

1. Make for the safe water buoy and pass close to it. It is the start of the channel.
2. Steer between "1" and "2". Green "1" goes to port and red "2" to starboard: red, right, returning.
3. At "B" the top band is red, so treat it as a red mark and keep it to starboard. The main channel continues to the left of it. Taking the right-hand branch means using the secondary channel.
4. You see a red light flashing quickly ahead. That is a Q R mark at a turn, so slow down and identify the next pair before altering course.

Common Mistakes

• Applying "red right returning" when heading out to sea. When outbound, red goes on your left.
• Assuming the same rule abroad. In Region A, red is on the left when returning.
• Confusing a junction mark with a lateral mark and taking the secondary channel.
• Ignoring the yellow ICW symbol where a waterway crosses an inlet channel.
• Steering straight at a buoy in a cross-current and being set onto it.
• Following a range beyond its safe (solid) section.

Summary

• The US uses IALA Region B: red, right, returning. Red marks are even-numbered nuns or triangles, and green marks are odd-numbered cans or squares.
• Numbers increase from seaward. The conventional direction around the coast is clockwise.
• Preferred-channel marks are banded, and the top colour decides how to pass them. Their light is Fl(2+1).
• Safe water (red and white, Mo(A)), isolated danger (black and red, Fl(2)), special (yellow) and cardinal marks are the same worldwide.
• Yellow triangles and squares show how to treat a mark along the ICW.
• Ranges are in line when you are on the track. Steer towards the rear mark to stay on it.

Check Your Understanding

1. You are returning to harbour and see a green can buoy numbered "5". On which side do you leave it? To port. Green cans are on your left when returning in Region B.
2. A junction buoy has a green top band. Which branch is preferred? The one that keeps the buoy on your port side, which is the branch to the right of it.
3. What does an isolated danger mark look like, and what light does it show? It is black with red bands and a two-ball topmark, and shows a white Fl(2) light.
4. A mark is red with a yellow square, and you are heading south along the ICW. On which side do you leave it? On your port side. Follow the yellow square for the ICW.
5. The rear range light appears to the left of the front one. Which way should you steer? To the left, towards the rear mark.