Navigation - General formulas

General Navigation Formulas. 

Topics Covered:

1. Plane Sailing

2. Parallel Sailing

3. Mercator Sailing

Plane sailing formula can be used generally up to 600 nautical miles, there after mercator sailing should be used. Sums are not presented as these are some basics in navigation.


1. Plane Sailing

N.1 - Plane Sailin

As these are right angles triangles,

Tan Co. = Depature / D.Lat
Sin Co. = Departure / Distance


The formulas above are sufficient to solve any given problem of plane and parallel sailing.

Cos Latitude = Departure / D.Long










2. Parallel Sailing.

The name itself gives the idea. It is sailing parallel on a particular latitude. The course will be due east (090) or due west(270).


The parallel sailing formula is,

• Cos. mean Lat = Dep / D.Long

when sailing parallel mean latitude is referred as Cos Latitude.





3. Mercator Sailing.

N.3 - Mercator Sailing

DMP = Diffence between Meridional Parts. Meridional Parts (MP) can be read from Traverse tables. Difference of Meridional parts can be calculated by either subtracting MPs or adding MPs.

Following fomulas can be derived,

• Tan Co. = DMP / D'Long

• Dep. = D'Long x Cos mean. Lat