Lesson 2 - Direction
A bearing is the direction between two specific objects, measured in degrees. For example, you might take a bearing from your position to a lighthouse to ensure you’re on the right course.
Course is the direction you intend to steer your vessel. It’s your planned path.
Heading is slightly different. It’s the direction your vessel is actually pointing at any given moment, which can be affected by wind, waves, or currents.
Course Over Ground (COG):
This is the actual direction your vessel is moving across the surface of the Earth.
Course Through Water (CTW):
This is the direction your vessel is moving relative to the water itself
Importance of COG (Course Over Ground) and CTW (Course Through Water)
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Safety
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Efficiency
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Navigation Accuracy
Compass Errors: Variation and Deviation
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Variation - Difference between True North and Magnetic North.
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Deviation - Magnetic interference from objects on your vessel
Correcting and Minimising Errors
When combining deviation and variation, it’s best to correct one at a time:
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Start with deviation to find your magnetic heading.
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Then adjust for variation to find your true heading.
Types of Compass
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Magnetic Compass: Simple, reliable, but prone to deviation.
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Gyro Compass: Uses gyroscopic inertia to find True North. It’s independent of the magnetic field but relies on power.
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Fluxgate Compass Uses electronic sensors to detect magnetic fields.
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