Navigation Basics
This basic navigational skill involves determining your position based on previously known positions and course and speed over time.
What is dead reckoning?
This is a scaled map specifically designed for navigation over water.
What is a nautical chart?
In dead reckoning, this is used to estimate the boat's current position.
What are speed and course?
This tool is used to measure angles, such as altitude, of celestial bodies.
What is a sextant?
This term denotes the vertical distance from the waterline to the lowest point of the ship.
What is draft?
This navigational tool is used to determine direction based on the Earth's magnetic field.
What is a compass?
These lines on a chart represent equal depth of water.
What are depth contours or isobaths?
In the past, this tool is used to calculate distance traveled in dead reckoning.
What is a log or odometer?
This device, often found on a boat, is used to measure speed through water.
What is a knotmeter or log?
The reference level from which depths are measured on a nautical chart.
What is Chart datum.
This is the difference between true north and magnetic north.
What is magnetic variation?
This item on a chart indicates the scale of the chart.
What is a chart scale?
This term describes the effect of wind and current on a vessel's path.
What is an estimated position?
This tool is used for drawing courses on a chart.
What are parallel rulers or a course plotter?
A unit of measurement used in marine navigation that is equivalent to one minute of latitude, or approximately 1.15078 miles on land.
What is a nautical mile
This is the practice of using the stars to navigate at sea.
What is celestial navigation?
This symbol on a chart indicates a potential hazard to navigation.
What is a navigation warning or obstacle symbol?
This is the traditional method of marking one's position on a chart.
What is plot or plotting?
This is a device that provides a visual representation of geographical and navigational data.
What is a chartplotter?
This refers to the direction or path along which something moves or along which it lies. In navigation, it's the direction to a particular point, usually given in degrees from north.
What is bearing
This part of a compass is affected by nearby metal objects or electronic devices, causing a deviation known as compass error.
What is the magnetic needle?
This is the system used to measure latitude and longitude on a chart.
What is a coordinate system?
This term refers to the measurement of the depth of water to ensure safe navigation. Soundings are typically marked on nautical charts to indicate the depth at various locations.
What are Soundings
This is the instrument used to determine the depth of water.
What is a depth sounder
These are the geographical coordinates used to specify the precise location of a point on the Earth's surface. Latitude measures north-south position, while longitude measures east-west position.
What are Latitude and Longitude