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Welcome to our free trial.
This free trial cover sections out of the Day Skipper,
Coastal Yachtmaster and Yachtmaster Ocean courses.
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Day Skipper level Course to steer.
If you were in a rowing boat rowing straight across a
flowing river you would be pushed down stream as you row.
Therefore,
instinctively you would angle the boat to point upstream
so that you can counter the flow and cross the river.
When we are out at sea it is not so easy to see the flow
and we often cannot see our destination.
Therefore, we
plot a course to steer to calculate how much to angle
the boat to counteract the tide and make the most direct
passage.
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The first step is very
straight forward.
Use the blue << and >> buttons to see the animation and stop it at the "End"
frame to see the whole picture.
Given information.
Boat
speed 5.5 knots.
Tide
260°(T). 1 knot.
Leeway 4° from a
westerly breeze.
Variation 7° west.
Deviation 4° east.
Start point (fix)
given in the animation.
Destination
(waypoint) given in the animation.
Steps.
Plot the fix and
waypoint.
Ground track.
Draw the ground track line, from the start
point (fix) extended through the destination
(waypoint).
Two arrows on the ground
track identify it on the chart.
Work out the distance.
The distance to the destination is required to
work out how long the journey will take and
how much tide to allow for.
With a boat speed of 5.5 knots the trip in
the graphic should take around 1 hour.
It is not necessary and prone to errors
trying to work out the tides and the journey
time for the exact distance. Work to the
nearest half hour.
Estimated boat speed 5.5 knots. 1 hour at
5.5 knots = 5.5 nautical miles. A 1
hour vector will be satisfactory for this
trip.
Work out the tides.
The direction and rate of the tide has to be
found for the correct hour of travel by
looking at the tide tables and then the
tidal diamond or stream information.
For this lesson the tide is given as1.0
knots 260°(T).
Draw the tidal vector.
The tidal vector, identified by three
arrows, is drawn
from the start point on a bearing
of 260°(T) 1.0 miles long
Plot the water track.
Using dividers measure 5.5 miles (boat
speed) from the latitude scale on the side
of the chart plot an small line, on the
ground track, 5.5 miles from the
end of the tidal vector. This is called the
intercept. Plot the water track from the end
of the tidal vector to the intercept. |
Please wait for the animation to load
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Using the plotter the true course to steer can be found from the water
track.
Leeway, if applicable, variation and
deviation.
To counteract
the wind the the skipper will need to steer
the boat towards the wind by the amount of
leeway expected given as 6° from a westerly
breeze.
Variation given as 7°
west will be added to the true course to
obtain the magnetic course.
Deviation given as 4° east will be subtracted from the magnetic course to
obtain the compass course to steer.
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Part of the navigation lights and shapes
section.
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Yacht motor sailing (Rule 25).
By day:
A yacht should display a cone pointing down when motor sailing to let
other vessels know that it is a power driven vessel under the rules.
At night:
WWhen motor sailing or motoring a steaming light and navigation lights
should be displayed. The tricolour should be turned off.
When sailing use navigation lights or the tricolour but never both.
In fog: When motor sailing 1 long blast at an
interval of not more than 2 minutes.
When sailing in fog sound 1 long and 2 short blasts at an interval of not
more than 2 minutes.
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Mouse over or touch to see lights
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Diver down (Rule 27).
By day:
A flag should be a rigid Morse A.
At night:
The lights displayed at night will depend on the type of vessel being used for the diving.
In fog: Sound Morse A, 1 short and 1 long blast, at an
interval of not more than 2 minutes.
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Mouse over or touch to see lights.
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Vessel restricted in ability to
manoeuvre (Rule 27) towing (Rule 24).
Vessel restricted in its ability to manoeuvre, towing another
vessel. Length of tow 200m or less.
By day:
Restricted in ability to manoeuvre is a ball, a diamond and a ball in vertical alignment.
At night: The restricted lights are 3 all round lights in a vertical line red, white, red.
Masthead lights (1 for the towing vessel and 1 for the towed vessel), sidelights, stern light and an amber towing
light in a vertical line with the stern light and of the same arc.
In fog: 1 long and 2 short blasts at
intervals of not more than 2 minutes. Towed vessel or last vessel in the
tow 1 long and 3 short blasts at intervals of not more than 2 minutes. |
Mouse over or touch to see lights.
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Vessel towing (Rule 24).
Towing with a length of tow over 200m,
starboard aspect.
By day:
Restricted in ability to manoeuvre is a ball, a diamond and a ball
in vertical alignment. Diamonds showing length of tow over 200m.
At Night: 3 white lights in a vertical line (1 masthead
light for the towing vessel and 2 masthead lights from the long tow), side lights,
stern light and an amber towing light in a vertical line with the stern
light.
In fog: 1 long and 2 short blasts at
intervals of not more than 2 minutes. Towed vessel or last vessel in the
tow 1 long and 3 short blasts at intervals of not more than 2 minutes.
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Mouse over or touch to see lights.
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Vessel engaged in underwater operations (Rule 27).
Vessel engaged in underwater operations, restricted in ability to
manoeuvre.
By day:
Restricted in ability to manoeuvre is a ball, a diamond and a ball
in vertical alignment. In addition 2 vertical balls on the side of the
obstruction and 2 vertical diamonds on the clear side.
At night. The restricted lights are 3 all round lights in a vertical line red, white, red.
2 vertical red lights on the side of the obstruction and 2
vertical green lights on the clear side.
When making way a masthead light(s) and navigation lights.
In fog. 1 long and 2 short blasts at an
interval of not more than 2 minutes. |
Mouse over or touch to see lights.
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Vessel engaged in fishing (Rule 26).
By day:
2 cones apexes pointing towards each other.
At night. 2 all round lights in a vertical line red over
white, with navigation lights.
Should be given a wide berth, as she may change direction unpredictably.
In fog: 1 long and 2 short blasts at an
interval of not more than 2 minutes. |
Mouse over or touch to see lights.
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Vessel engaged in Trawling
(Rule 26).
By day: Cone indicates direction of nets extending over 150m
horizontally. 2 cones apexes together indicates fishing.
At night.. 2 all round lights in a vertical line green over
white, with navigation lights.
In addition if she has gear extending more than 150 m horizontally
into the seaway she would show a lower white light in the direction of
her gear.
In fog: 1 long and 2 short
blasts at an interval of not more than 2 minutes.
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Mouse over or touch to see lights.
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Vessel constrained by draught
(Rule 28).
By day: Cylinder shape.
This vessel is restricted in her movements. Do not obstruct this vessel.
At night:
3 all round
lights in a vertical line red red red, masthead light(s) and navigation
lights in addition to the above.
In fog: 1 long and 2 short blasts
at an interval of not more than 2 minutes. |
Mouse over or touch to see lights.
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Vessel at anchor (Rule 30).
By day: A black ball where it can best be seen.
At night: Under 50m 1 all round white light where it
can best be seen. Over 50m the light should be in the forepart of
the vessel and an additional light should be displayed aft and lower
than the forward light.
If the vessel is over 100m available lights should be used
to light her decks.
In fog: At intervals of not more than 1 minute rapid ringing
of a bell for about five seconds. In a vessel of 100m or more the bell should in
the forepart of the vessel followed by a gong sounded
rapidly for a further five seconds.
In addition when at anchor a vessel my sound 1 short 1 long and 1
short blast to warn other ships in the vicinity if there is a risk of
collision. |
Mouse over or touch to see lights.
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Vessel not under command (NUC)
(Rule 27).
By day: 2 black balls
vertically aligned.
This vessel is severely restricted in her ability to deviate from her
path. Do not obstruct this vessel.
At night: 2 all round red
lights.
When making way sidelights and stern light should be displayed in
addition to the above.
In fog. 1 long and 2 short blasts
at an interval of not more than 2 minutes. |
Mouse over or touch to see lights.
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Vessel aground (Rule 30).
By day: 3 black balls in a vertical line.
At night: 2 vertical red lights and the vessel's anchor light(s).
In fog: At intervals of not more than 1 minute 3
separate and distinct strokes on the bell followed by rapid
ringing of a bell for about five seconds then a further 3 strokes
on the bell .
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Mouse over or touch to see lights.
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Vessel restricted in ability to manoeuvre
(Rule 27)
By day. By day displays a ball diamond ball vertically.
At night.
3 all round lights in a vertical line red white
red, with standard navigation lights and masthead lights.
In fog: 1 long and 2 short blasts at an interval of
not more than 2 minutes. |
Mouse over or touch to see lights.
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Minesweeper (Rule 27)
By day: 3 balls in a triangle shape.
At night. 3 all round green lights in the shape of a
triangle, with standard navigation lights and masthead lights.
In fog. 1 long and 2 short blasts
at an interval of not more than 2 minutes. |
Mouse over or touch to see lights.
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