The right way to Discover Latitude and Longitude on a Marine Chart
Any GPS receiver will discover latitude and longitude alongside your navigation routes always. However as skipper, have you ever plotted this data on a nautical chart to confirm your place? Take your crusing expertise to the subsequent degree with this important crusing ability!
Navigate with Latitude
Cartographers create a grid-like canvas in your navigation chart. Latitude traces run in a horizontal course. Strains of longitude run in a vertical course. Think about the earth, balanced on its axis with out inclination. Wrap a “belt” across the earth, divide it in half and you’ve got the equator – the birthplace of Latitude. Label the equator 0 levels.
Latitude traces are parallel to the equator within the north or south. To plot latitude for the place you’re, you measure what number of levels you’re north or south of the equator. The latitude reaches a most of 90 levels on the north and south poles. At all times label Latitude N, if north of the equator, or S, if south of the equator.
In map navigation, use the precise or left scales to search out your latitude. These scales are damaged down into levels, minutes and tenths of a minute, or levels minutes and seconds. One diploma of latitude is equal to sixty minutes; one minute of Latitude equals sixty seconds. Here is a easy solution to keep in mind:
1 diploma = 60 minutes.
1 minute = 60 seconds.
Navigate with longitude
Return to your imaginary globe. To measure longitude, you once more divide the earth in half, however this time lengthwise. Find Greenwich, England in your globe. Draw a line across the earth that intersects Greenwich and the north and south poles. Cartographers name this the Greenwich, or prime meridian – the cradle of longitude. Label the Greenwich meridian 0 levels.
Strains of longitude are parallel to the vertical meridian of Greenwich within the east or west. To search out longitude, you measure what number of levels you’re east or west of the Greenwich meridian. Longitude reaches a most of 180 levels on the far aspect of the earth on the Worldwide Date Line. You have to point out longitude E, if east of Greenwich, or W, if west of Greenwich.
Use the highest or backside of the graph to measure longitude. Like latitude, longitude is damaged down into levels, minutes and tenths of minutes or levels, minutes and seconds.
The right way to Convert Minute Increments
All nautical charts present minutes damaged down into increments so you’ll be able to plot elements of a minute. For instance, in case your GPS place signifies 23-13N; 82-16W, there are not any increments to fret about. However, in case your GPS place signifies Latitude 23-13.278N; Longitude 82-16.786W, you could have minute increments. Earlier than plotting your place, around the increments to the closest tenth of a minute. Spherical it up like this: Latitude 23-13.3N; Size 82-16.8W.
Take a look at the latitude scales (proper or left aspect) and longitude scales (up or down) in your map. Are minutes damaged down into tenths or seconds?
Some charts show levels, minutes, and tenths of a minute. The minutes can be divided into 10 small segments. Every small section equals one tenth of a minute. Different graphs show levels, minutes and seconds of a minute. In case your graph shows levels, minutes and seconds, you’ll need to multiply the “tenths” of a minute by 6. Observe this instance:
GPS studying (with rounded minutes as beforehand described): Latitude 23-13.3N; Size 82-16.8W.
Multiply the latitude minute increment like this. 3 X 6 = 18 seconds.
Multiply the increment of minutes of longitude like this. 8 X 6 = 48 seconds.
Monitor: Latitude 23 levels, 13 minutes, 18 seconds; Longitude 82 levels, 16 minutes, 48 seconds.
The right way to plot latitude and longitude
Use a pair of separators to plot your place by Lat and Lengthy on the chart. Learn levels and minutes out of your GPS. Discover the closest levels and full minute of latitude in your GPS.
For instance, for Latitude 23-13.3N, you’re in search of 23 levels, 13 minutes on the precise or left scales in your navigation chart. Push some extent out of your dividers inside 13 minutes. Open the opposite leg 3 small segments (three tenths), above the 13 minute mark. In case your chart is displaying seconds as a substitute of tenths, open the opposite leg of your dividers 18 seconds (0.3 x 6) above the 13 minute mark. Place a pencil mark the place the dividers contact the precise latitude.
Subsequent, plot your longitude. Use the very same methodology to plot your longitude. Be sure you use the scales on the high or backside of the graph to plot your longitude. When you could have discovered your longitude, place a pencil line the place the dividers contact the precise longitude.
Discover your actual location
Line up your parallel rulers or different straight rulers in order that the highest lengthy edge touches the Latitude pencil mark. Make the parallel rulers or the straight ruler perpendicular in order that once you draw the road of latitude will probably be parallel to all the opposite traces of latitude. Draw a skinny pencil line throughout the physique of the map to a location close to the place you marked the higher or decrease longitude scale.
Repeat this identical methodology to align and draw your line of longitude. The place the longitude pencil line intersects, the latitude pencil line signifies your actual location. It is best to now have a cross. Place some extent the place the 2 traces intersect. Circle the dot. Erase the sunshine traces drawn from the perimeters of the graph to scrub up the graph and hold your plot clear.
Use these easy steps to rapidly discover latitude and longitude in your nautical chart. With these crusing expertise, you may be properly in your solution to changing into a assured skipper, wherever you select to sail!
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