Types of Compas Flashcards
What is the ship’s compass?
a large compass at the helm of the ship, often used for steering.
What is the advantage of a fixed compass?
as it doesn’t move around the vessel it can be corrected for magnetic deviation.
How would you work out your vessels magnetic deviation?
you would turn the boat through 360 while on a set transit, and compare readings from the ship’s compass to the known bearing of the transit, allowing you to correct the compass.
what is a hand bearing compass?
a compass that has a sight, which allows you to take bearings to visible objects.
what are two good uses of a hand bearing compass?
1) taking bearings to fixed objects to get a position fix
2) taking constant bearings to an approaching vessel to determine collision risk.
what must be carefully considered when using a hand bearing or other mobile compass, and what can be done about it?
the magnetic deviation on the ship varies across the deck, so the bearing could be inaccurate. to combat this, the compass should be used as far away from any ferous metals or magnetic objects that could cause deviation.
what is a fluxgate compass?
a fluxgate compass is an electronic compass that senses the magnetic field of the earth electronically.
what are the advantages of a fluxgate compass?
it has no moving parts as it just uses electronics to sense the magnetic field. The compass bearing can be digitised and used on chart plotters or autopilots. it can be electronically corrected for deviation.
