Pilotage

1
Pilotage

• Mark Powell
• Mole Valley Sub Aqua Club
• SAA - 101

2
Objectives

• At the end of this lesson you should know
• the purpose of pilotage
• Many of the signposts used in pilotage
• how to obtain pilotage information from charts

3
Outline

• Pilotage and charts
• Buoys and markers
• Lights
• Leading lines and lights
• Natural pilotage features

4
What is Pilotage?

• Use of visible, physical features as guides
• Pilotage is needed
• Close to shore or in confined waters
• In shallow or dangerous water
• Types of pilotage features
• Lights and man made marks placed at key spots
• Identifiable natural features

5
Pilotage and Charts

• Charts show many pilotage symbols
• Chart is a source of detailed local knowledge
• Can use charts both ways
• Find nearby chart symbols and then look for them
  at sea
• Measure direction of feature observed at sea and
  plot it on a chart

6
Lights and Markers

• Markers buoys and posts used in pilotage
• Have shape, colour, topmark and meaning
• Markers may have lights for use at night
• Lights identified by their flashes and colours

7
Lateral Markers

• Mark the edges of channels
• Port marks the left bank on rising tide
• Starboard marks the right bank on rising tide
• Colour and shape red cans and green cones

8
Direction of Lateral Buoyage

• Keep Red to left and Green to right in direction
  rising tide
• Example On which side do you pass the lateral
  buoys?

• Going in direction of rising tide

• Going in direction of falling tide

9
Direction of Rising Tide

• Some places are confusing
• Split Estuaries Solent
• East coast estuaries
• Direction of Buoyage symbol highlights the
  direction

10
Cardinal Markers
Safe water to the west

• Point to safe water
• Top mark like 4 points of compass
• Colours
• 3 bands of yellow or black
• top marks point to black
• Often named on charts
• Light flashes like hours on clock

9 quick flashes every 15 sec. Or 9 v. quick
flashes every 10 sec.
11
All four Cardinal Markers
N
Danger
W
E
S
12
Safe Water Marker

• Indicate start of deep water
• Round top mark
• Red and white colour
• May have a white Isophase or Occulting light

13
Isolated Danger Marker

• Indicate a hazard
• Two round top marks
• Red and black colour
• May have a White, Group Flashing 2 light

14
Special Markers

• Show boundary of administrative area
• Speed limit, swimming, anchoring
• May have a cross top mark
• Yellow colour
• May have a yellow light

15
Light symbols characteristics
16
Light characteristics
17
Chart symbols for buoys and lights

• Major light, minor light, light, light house

• Lateral buoys and marks

• Cardinal buoys and marks

• Safe water buoys and marks

• Isolated danger buoys and marks

• Special buoys and marks

18
Leading lines and lights

• Line indicates a safe course near hidden dangers
• Often guide boats up inlets into harbour
• Leading line formed by two markers day use
• Leading lights formed by two lights night use
• Lines shown on charts
• Compass bearing of line shown on chart

19
Leading lines
20
Leading lights
21
Natural features for pilotage

• Fixed points
• Individual rocks often difficult to see and
  identify, can be dangerous
• Shoreline difficult to positively identify, can
  be misleading
• Headlands and bays - can be misleading
• Directions and lines
• Transits and compass bearings
• General areas
• Depth need to calculate tidal height, uncharted
  depth changes

22
Summary

• Pilotage and charts
• Buoys and markers
• Lights
• Leading lines and lights
• Natural pilotage features

23
Self Check

• What is the purpose of pilotage? When is it used?
• Name some man-made natural pilotage features
• Describe all 5 types of buoy (shape, colour,
  lights and meaning)?
• What is the direction of buoyage? Its symbol?
• What do these chart symbols indicate?

• What do these chart symbols indicate?