Position Fix Flashcards
What does LOP stand for?
Line of Position
What is the Three Point Fix?
Take three different bearings from the vessel to various different objects
How far apart should the objects you take bearings to be in Three Point Fix?
Between 30º and 150º
What is one thing you should avoid when taking bearings for Three Point Fix?
Buoys
What information do you need to work out Dead Reckoning?
Your starting position, the direction you are travelling and the distance you travelled
Why is accuracy for Dead Reckoning limited?
Doesn’t take into account tide
How do you work out Dead Reckoning?
Mark your starting position on a chart, draw a line in the direction you are heading using Portland Course Plotter and then use the ships log to work out distance travelled and use your dividers to mark out distance travelled and you have DR
Where do you find out tidal information?
Tide Tables and Tidal Atlasses
What information do you need to work out Estimated Position?
Dead Reckoning Tidal information (Set and Drift)
How do you work out Course Over Ground?
Draw a line from the starting position to Estimated Position
True or False?
If the journey time from your starting positioning to DR is more than an hour you will need more than one tidal vectors
True - one tidal vector for each hour
How do you work out Speed Over Ground?
Divide Course Over Ground with how long it took to get there
What is Leeway?
The effect wind has on the vessel
When do we use Leeway?
Before we plot Dead Reckoning
When is Running Fix useful?
When travelling around a coast
