Navigation

NAU 102

Lesson 9

Navigation Aids

Beacons

Manmade objects intended to help fix the vessel’s position and avoid hazards.

Buoys

Lights

Ranges

Fog Signals

Pharos Lighthouse

• Alexandria, Egypt• 1st century A.D.• Masonry construction• Height (est.) 377-492 ft.• Visible range: 35 miles• Used fires & reflective

mirrors

Navigation Aids

Some private aids maintained by:

U.S. Coast Guard operates and maintains U.S. navaids.

State governments

Other federal agencies

Individuals/Companies

Buoys

•Mark channels

Floating navaids

Anchored to the bottom

•Indicate shoals & obstructions

•Warn of dangers

Buoys

Convey information by:

•Shape •Color

•Letters or Numbers

•Audible Signal

•Light•Topmark

Buoys

•Reflective tape

Common equipment:

•Radar reflectors

•Sound signals

•Bells & Gongs

•Whistles & Horns

Buoys

•Cardinal marks

Types of Buoys

•Lateral marks

•Special marks

•Safe water marks

•Isolated danger marks

Lateral Marks

•Sides of channels

Navaids mark:

•Channel junctions •Channel bifurcations

Cardinal Marks

Indicate direction of navigable water.

Show cardinal directions (N, S, E, W) of safe water

•E.g. Always pass to the North of a North Cardinal Mark

•Note: cardinal marks are not used in U.S. waters

Safe Water Marks

Indicate an area of safe (navigable) waters.

•E.g. Mid-channel & fairway buoys

Isolated Danger Marks

Navaids mark points of danger.

•E.g. Submerged wreck

Special Marks

•Traffic separation schemes

Navaids mark special features of interest:

•Anchorages

•Recreational zones

•Etc.

Lateral Systems

Historically there have been many buoyage systems in the world.

1970s - International Association of Lighthouse Authorities (IALA)

simplified the system

IALA Buoyage Systems

Two major international systems:

•IALA - B•IALA - A

•Europe

•Africa

•Most of Asia

•Australia

•New Zealand

•North America

•South America

•Japan

•Philippines

•South Korea

IALA Buoyage Systems

Direction Conventions

Based on entering from seaward.

E.g. The right (or starboard) side of a channel is to starboard of vessel entering

from sea.

E.g. The right side is to port of a vessel heading towards the sea.

Direction Conventions

Many places “entering from seaward” is not clear.

E.g. Along coasts and Intracoastal waterways.

Clockwise direction around U.S. is treated as entering.

Direction Conventions

Lateral Colors

Red to starboard

IALA - B

Green to port

“Red-Right-Returning”

Red buoys and green buoys mark the sides of channels

Lateral Colors

IALA - A is opposite.

Lateral Colors

Horizontal Red & Green Bands

Mark junctions & bifurcations

Top color indicates preferred channel.

Lateral Colors

Cardinal Colors

Horizontal Black & Yellow Bands

Safe Water Colors

Red & White Vertical Stripes

Isolated Danger Colors

Black & Red Horizontal Bands

Special Marks Color

Solid Yellow

Buoy Shapes

5 Basic Shapes

Can

Cone (Nun)

Sphere

Pillar

Spar

CAN BUOYS

• Shaped like a tin can

• Cylindrical shape or appear cylindrical

• Flat top when seen from a distance

Buoy Shapes

Can

•Mark port side of channels

•Mark channel junctions –

preferred channel to starboard

Buoy Shapes

Can

Buoy Shapes

Conical / Nun

•Mark starboard side of channels

•Mark channel junctions –

preferred channel to port

Buoy Shapes

Conical / Nun

Buoy Shapes

Spherical

(Globe shape)

•Only used for Safe Water Marks

•Always have red and white vertical

stripes

PILLAR BUOY

• Sometimes referred to as a “Lighted Buoy” or a “Whistle Buoy”

• Lights used to make them visible at night; use batteries and/or solar receptors

• Have a short tower often skeletal in construction mounted on a visible float that may have a light, gong, whistle or other accessory

Buoy Shapes

Pillar

•Any type of buoy

•Often lighted

•Tall, central structure on broad base.

•Color & topmark indicate type

Buoy Shapes

Pillar

Buoy Shapes

Spar

•Any type of buoy

•Often lighted

•Usually not floating, driven into

bottom.

•Thin cylinder/pole

Buoy Shapes

Isolated danger marks and special marks may be any

shape.

•Pillar or spar are preferred.

BELL BUOY

• Has a bell with several clappers (usually four) externally hung

• Clappers will strike the bell as it rocks with the motion of the sea

• CAUTION: Bell may not ring in calm seas

GONG BUOY

• Similar in construction to a Bell Buoy

• Has several gongs mounted in a vertical stack, each sounding a different note

WHISTLE BUOY

• Similar in construction to a Bell or Gong Buoy

• Has a low-pitched whistle signal that is activated by the rise and fall of the buoy in a seaway; may not sound in calm waters

• Sometimes produces a moaning sound

HORN BUOY

• Similar to a Whistle Buoy except that its sound signal is electrically powered by batteries in the lower part of the buoy

• Usually produces a higher note that a Whistle Buoy with a more regular sound pattern

Topmarks

Shapes attached to pillars and spars.Indicate type of mark.

Square = port side Cone = starboard side

Lateral Marks

Topmarks

Isolated Danger

2 Spheres, one above the other

Topmarks

Safe Water

1 Sphere

Topmarks

Special Purpose – Yellow X

Topmarks

Double Cones = Cardinal Marks

North South East West

Topmarks

•North points up.

•South points down.

•West looks like a Wine glass.

•The points point to the black

stripe(s).

Introduction to Navigation

Questions?