Back in the old days if you were presented with a reroute when oceanic, you pulled out the charts and plotter and got to work building a new flight plan. If you were good, you could churn out three thousand miles of master document in about fifteen minutes. If you were really good, you had a book of ten degree tables and could cut that time in half.
— James Albright
Updated:
2013-12-28
These days I would just call in the change to my flight planning service and have them fax, e-mail, or just read them to me over the phone. What if you don't have that kind of connectivity or if you just want to be old school for a day?
I haven't seen any published ten degree tables in years. They used to appear in Jeppesen manuals and every now and then you see an abbreviated form. I once worked in a management company for a director of operations who grew up with these tables and often waxed poetic about why they were vital, even today. So, exercising my highest level of OCD, I wrote a set from the equator to 65° latitude (north or south). It took me a week so I kept a copy for myself. You can download a printed set here: True Course 10 Degree Tables.
1
Purpose
If required to fly an unplanned oceanic flight plan — you got a reroute just prior to coast out — you need to build a new master document with courses and distances between waypoints so you can still make all the necessary checks before each point and also so you can make your post position plot. The 10 degree tables below provide your true courses and distances between any two positions expressed as latitudes (to the nearest degree) and the next position expressed as a longitude 10 degrees east or west.
For example, say you are 50°N 030°W heading to Europe and your next position will be at 51°N 020°W. You could pull out a plotter and come up with a course, add the variation, and end up with the correct true course. Then you could measure the distance, compare that to the nearest line of longitude and come up with a distance. You would probably do this a few times to make sure you didn't make a mistake, either with the plotter or your ad hoc measuring device. Or you could go to the From 50° Latitude table, check the course provided on the 51° row and Northern Hemisphere / East column and see your true course will be 081° and reading across see that the distance between these two points is 386 nautical miles.
2
Initial versus midpoint courses
True Course initial vs. midpoint vs. ending
The 10 degree tables provide the course at the midpoint between two positions. This will agree with your plotter if you put the center of the compass over the midpoint.
Most FMS (and many flight plans) print the initial course leaving the waypoint. The difference can be significant. When checking your progress, make sure you understand what the FMS is telling your, what you are seeing on the 10 degree table, and what you see with a plotter on a chart.
More about this: Initial vs. Midpoint Course.
3
The tables
From 00° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 01° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 02° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 03° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 04° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 05° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 06° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 07° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 08° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 09° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 10° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 11° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 12° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 13° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 14° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 15° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 16° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 17° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 18° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 19° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 20° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 21° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 22° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 23° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 24° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 25° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 26° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 27° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 28° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 29° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 30° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 31° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 32° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 33° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 34° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 35° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 36° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 37° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 38° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 39° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 40° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 41° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 42° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 43° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 44° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 45° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 46° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 47° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 48° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 49° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 50° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 51° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 52° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 53° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 54° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 55° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 56° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 57° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 58° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 59° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 60° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 61° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 62° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 63° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 64° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
From 65° Latitude
To determine the average true course and distance between two points which are ten degrees apart in longitude:
- Find the table with the starting latitude (North or South doesn't matter)
- Find the corresponding latitude in the second column. (If there are two choices, the latitude on top is in the same hemisphere (North or South)
- Read the true course underneath the desired hemisphere and direction of travel (east or west)
- Read the distance in the last column
