ABL-9
Able
Navigation Rules
Instructors: George Crowl
Course Outline
a. Demonstrate a working knowledge of Navigation
Rules, International and Inland.
b. Explain vessel lights for the following: towing
(astern, alongside, pushing ahead, and cannot
deviate), fishing, trawling, restricted maneuverability,
underwater operations, constrained by draft, and
aground.
Course Outline
e. Read in detail a National Ocean Service (NOS)
chart, preferably for the area normally cruised by
your ship, identifying all marks on it.
f. Explain the use of tide tables, current tables, light
lists, and how to update a chart using the Notice to
Mariners.
ABL-9a
a. Demonstrate a working knowledge of Navigation
Rules, International and Inland.
Rules of the Road
 Like traffic rules on
our highways
 Inland and International Rules are very similar, in
one document on-line
 “Demonstrate” means “do it” on the water
 In addition, show knowledge of what to do in less
likely circumstances
ABL-9b
b. Explain vessel lights for the following: towing
(astern, alongside, pushing ahead, and cannot
deviate), fishing, trawling, restricted maneuverability,
underwater operations, constrained by draft, and
aground.
ABL-9c
c. Describe special lights and day shapes deployed on
the following vessels: not under command, restricted
by ability to maneuver, constrained by draft, fishing
(trawling), and sailing vessels under power.
Dayshapes
 Seen
during day
 Serve same functions as lights at night
 Hoisted vertically in rigging
 Diamond
(white light)
 Ball (usually red light)
 Cone (green or red light)
 Cylinder (3 red lights)
Review – Navigation Lights
 Red,
green and white
 Green – bow to 112.5° starboard
 Red – bow to 112.5° port
 White – relative bearing 112.5° to 247.5°
Lights on Towed Vessel
 Normally, towed
and sternlight.
vessel displays standard sidelights
Lights Towing Astern <200M
 Normal
power lights
 + One masthead light
(= two total)
 + One yellow stern light
 “Yellow over white, my towline is tight”
Lights Towing Astern >200M
 Three masthead lights
 (Also a
diamond day shape)
Towing Alongside
 Towed vessel has
standard
lighting
 Two masthead lights, side lights
 International – one white
sternlight
 Inland –
two yellow towing
lights
“Yellow over yellow, a pushing or hip towing fellow.”
Lights Pushing Ahead
 Pushed vessel has
sidelights (+ flashing Inland)
 Pushing vessel has two mastlights and sidelights
 International – Pushing vessel white sternlight
 Inland – Pushing vessel two yellow towing lights
Towing Cannot Deviate
 Towing vessel shows both towing
lights and
restricted maneuverability lights
 Two / three towing lights on top
 Red / white / red lights below them
 Ball / diamond / ball dayshape
Sailing Vessel Under Power
 Sails may
be up
 Dayshape – cone, apex down, on front of
boat
 Normal sidelights and sternlight
 One 225° mast light, usually about 2/3
way up the mast
 Colloquially called “steaming”
light
Sailing Vessel Under Sail
 Any of
the light combinations below
 Red over green, sailing machine
Fishing Vessel
 Applies
only to fishing that restricts maneuverability
(mostly commercial)
 Must be actively engaged in fishing
 “Red over white, fishing tonight”
 Dayshape – cones,
apex to apex
Trawling Vessel
 Applies
only to trawling that restricts maneuverability
(mostly commericial)
 Must be actively engaged in trawling
 Green over white, trawling tonight
 Dayshape – two cones,
apex to apex, same as
fishing
Restricted Ability to Maneuver
 Red
over white over red
 Ball / diamond / ball dayshapes
 White mast top light shows it is also anchored
 Single ball dayshape shows anchored
Underwater Operations
 Dredging, diving, other
underwater operations
 Red, White, Red on vessel center
 Two red on obstruction side
 Two green on passing side
 Ball / diamond / ball, with diamonds and balls
Constrained by Draft (Intl)
 Too deep
to leave the channel
 Three red lights in vertical row
 International Rules only
 Dayshape – cylinder
 “Three reds in a
row, no room
below”
Vessel Aground
 Two
vertical red lights
 One all around white light
 Dayshapes – three balls
Not Under Command
 Two
vertical red lights
 Sidelights, sternlight, no masthead light
 Two ball dayshapes
 “Red over red, the
captain's dead.”
Vessel Priority
 Airplanes /
WIGs / etc.
 Power vessel
 Tow boats (power vessel)
 Sailboat under power (power vessel)
 Fishing / trawling
 Restricted in ability to maneuver
 Constrained by draft
 Aground / not under command
Identify Type Boat
N
Questions?
 Questions first?
 Vessel Priority in
Rules of the Road (ORD-9)
 Shown you lights and dayshapes that identify a
vessel in the vessel priority
 Know your place in the vessel priority (pretty low!)
 Be prepared to take appropriate action
 Come back and show us you know this material and
can apply it.
ABL-9d
d. Understand the system of aids to navigation
employed in your area. Include buoys, lights, and
daymarks, and their significance and corresponding
chart symbols.
Aids to Navigation (ATON)
 ATONs are
like street signs on a road
 Nautical chart displays their locations and what they
are
 Symbols identified in Chart 1 (available on-line)
 Three main ATONs

Daybeacons (poles)

Buoys

Lights (both poles and buoys)
 Several lesser kinds of ATONs
Lateral System
 Establishes channels
and marks to guide vessels to
stay within those channels
 Two main colors

Red on the Right Returning from the sea,
triangular shape

Green on the left returning from the sea, square
shape
 Channel limits marked by red and green lights,
buoys, and daybeacons
Daybeacons
 Used
in shallow water
 Mounted on a pole, numbered
 Red daybeacons triangular shape
 On right-hand side of channel
going inbound to dock
 Green daybeacons square shape
 On left-hand side
of channel going
inbound to dock
Buoys
 Floating aids, anchored to
bottom, numbered
 Can move a little, tide, current
 Red, triangular top, “nun”
 Green, square top, “can”
Lights
 Lights on
buoys and on poles
 Basic buoy or daybeacon
 Light mounted on top
 Light has pattern to flash for
identification
Junctions
 Junctions are
where two channels meet
 Color on top is for the primary channel
 Lower color is for the secondary channel
 Junctions are lettered, not numbered
Ranges
 Ranges
are two sets of panels
or lights in a line that show
the proper channel
 Panels / lights connected by
dashes on chart to channel
Regulatory / Information Marks
 White buoy, red
 Four main
letters
types
 Information, Regulation, Prohibit, Danger
ABL-9e
e. Read in detail a National Ocean Service (NOS)
chart, preferably for the area normally cruised by
your ship, identifying all marks on it.
Chart 1
 Chart
1 available in hard copy and on the internet.
Google Chart 1.
 Chart 1 has everything! A Sea Scout should not
memorize Chart 1.
 Common chart symbols are somewhat intuitive
 Numbers in the middle of the water are depths
 Little green squares and red triangles are
daybeacons
 Lights have a purple “beam” coming from them
ABL-9f
f. Explain the use of tide tables, current tables, light
lists, and how to update a chart using the Notice to
Mariners.
Tide Tables
 Apply to
coastal areas only, not to inland waters
 Tide tables give the time and height of high and low
tides at specific locations
 Based on astronomical data (the Sun and Moon)
 Tides also vary according to the weather, strong
northerly winds will push water out of a bay that has
a southern entrance. Weather effect is not predicted
in tide tables.
 http://tidesandcurrents.noaa.gov/tide_predictions.ht
ml
Two Tables
Current Tables
 Tides cause currents, especially in
restricted
waterways
 Think: Under the Golden Gate Bridge
Out Bolivar Roads next to Galveston
 Minimum flow: near high and low tide times
 Maximum flow: midway between high / low times
 Not always true, but a good start
 Varying depths, varying speeds. Sea Scouts use 6
feet or so, shallower draft.
Two Different Currents
6
foot depth, Red Fish Island, Morgans Point, both
on Houston Ship Channel, 40' deep channel
 Current will not apply in 7' water depth 100 yards
west of HSC
 Redfish
Flood 0.7K 341° Ebb 0.7K 154°
 Morgan Pt Flood 0.5K 336° Ebb 0.7K 163°
Calculating Speed
 Maximum speed
is displayed in table
 Determine time for maximum speed
 Determine time for slack water
 At 1/3 of the time from max to slack, speed will be
90% of maximum
 At 2/3 of the time from max to slack, speed will be
50% of maximum
 Interpolate as needed
Light Lists
 USCG
publishes electronically. Google “Light List,”
click on your local area
 Lists each navigational aid (ATON) that the USCG
and private parties maintain.
 Unique identifier, lat / long, full description
 Coordinates in DDD-MM-SS.SSS
 You can put them into your GPS in MM-SS,
then switch your base to MM.MMM, the GPS will do
the conversion automatically for you
Sample Light List
L
Notice to Mariners
 Published weekly by
USCG
 Identifies changes to Light List, charts, other nautical
publications.
 Publishes coming changes and activities that affect
the water, such as dredging, etc.
 Available online, Google “Notice to Mariners”
Local Notice to Mariners
 Downloadable
from USCG
Typical Discrepancy Page
 Lt
# Description Discrepancy Chart
St Dt
To Make Corrections
 Look at
the chart number in each list
 Annotate your chart if needed
 For instance, if a light has been destroyed, mark it
DEST or some way you understand
 If a light is back in service, mark OK on chart
Summary
 Navigation Rules
 Lights
 Day
Shapes
 ATONs
 Chart Symbols
 Publications
Practical Knowledge
 Go
out and demonstrate the practical knowledge you
must display to pass this requirement
Questions?
