Navigational Instruments & Compasses

What is the purpose of a compass in navigation?

• The purpose of a compass in navigation is to calculate speed.

• The purpose of a compass in navigation is to determine direction.

• The purpose of a compass in navigation is to measure temperature.

• The purpose of a compass in navigation is to estimate distance.

Name one traditional navigational instrument used by sailors.

• Sextant

• Astrolabe

• Gyroscope

• Compass

How does a sextant work for navigation?

• A sextant relies on GPS signals for navigation

• A sextant measures the distance between two points on a map

• A sextant measures the angle between a celestial body and the horizon to determine the observer's position on Earth.

• A sextant uses magnetic fields to determine direction

What is the difference between a magnetic compass and a gyrocompass?

• A magnetic compass uses the sun's position, while a gyrocompass uses the moon's position.

• A magnetic compass relies on Earth's magnetic field, while a gyrocompass uses the rotation of the Earth to find true north.

• A magnetic compass is digital, while a gyrocompass is analog.

• A magnetic compass is used on land, while a gyrocompass is used at sea.

Explain the concept of declination in relation to compass navigation.

• Declination is the process of aligning a compass with the magnetic field to determine direction.

• Declination refers to the distance between two points on a map used for navigation.

• Declination is the term for the angle at which the sun sets in relation to compass readings.

• Declination is the angular difference between true north and magnetic north, crucial for adjusting compass readings for accurate navigation.

What is an astrolabe and how was it used for navigation?

• An astrolabe is a tool for measuring wind speed and direction.

• An astrolabe is a type of compass used to determine direction at sea.

• An astrolabe is a modern GPS device used for navigation on land.

• An astrolabe is an ancient astronomical instrument used to determine the altitude of celestial bodies, such as the sun or stars. It was used for navigation by measuring the angle between the horizon and a celestial body, allowing sailors to determine their latitude at sea.

Describe the function of a GPS in modern navigation.

• GPS in modern navigation communicates with other vehicles

• GPS in modern navigation provides real-time traffic updates

• GPS in modern navigation determines location using signals from satellites.

• GPS in modern navigation tracks weather patterns

What is a nautical chart and how is it used in navigation?

• A nautical chart is a map used in navigation to plan routes, determine positions, and avoid hazards at sea.

• A nautical chart is a type of compass used in navigation to find directions at sea.

• A nautical chart is a musical instrument used in navigation to entertain sailors.

• A nautical chart is a type of telescope used in navigation to spot land from afar.

What are the main components of a marine compass?

• magnetic card, casing, direction line, travel arrow, north needle

• compass rose, casing, direction line, travel arrow, magnetic needle

• compass card, casing, direction line, travel arrow, north needle

• compass card, housing, lubber line, direction-of-travel arrow, magnetic needle

How does a chronometer help in determining longitude at sea?

• By measuring the air pressure

• By analyzing the water temperature

• By observing the stars

• By comparing the time at a reference location with the local time to calculate the longitudinal difference.