Determining the ship’s speed using the log speed. For electro-mechanical and impeller-type logs, the Log Correction (or Log Coefficient) does not vary with vessel speed. The Log Speed turns into True Speed using the Log Correction (or Log Coefficient). Just as for the distance correction.
Category: Basic Knowledge
Measured Distance. The Measured Distance: The distance between the crossing leading lines of an Experimental Range.
Experimental Range. The Experimental Range: Is a maritime area near and parallel to the coast, arranged for carrying out various trials with the ships, such as:
The log in a region with marine currents. To determining the Log Correction or Coefficient in a region with marine currents, proceed as follow:
The Log Coefficient. Determining the travelled distance. The log coefficient: The ratio between the True Distance travelled by ship and the Log Distance indicated by the log.
The Log Correction. Determining the travelled distance: The Log Correction: is the value, expressed as a percentage, which must be applied to the Log Distance to find out the True Distance travelled by ship.
The Log History: This post, ‘The Log History’, has connection with the history of maritime navigation, and not with the modern navigation. But, are interesting.
The Log. General knowledge on travelled distance: The Log: Navigation device on board of the ships used for measuring speed and distance travelled in a given time.
Determining the compass deviation in 36 courses: Determining the compass deviation in 36 courses is not a separate method, it includes all navigation methods that have been described before.
Determining the compass deviation by comparing of courses: The procedures for determining the compass deviation described up to here were based on the comparison of bearings.