Aim and Materials Required

Aim and Materials Required

Aim: To fix a vessel position by taking cross bearing or bearing and distance

Learning Outcome: At the end of this practical,students will understand the method of fixing vessels position by cross bearing and bearing and distance.

Materials Required: Parallel ruler, compass, pencil

Procedure:

Bearing

Bearing of an object is the direction in which an object is visible or lies from the observer on a vessel. The following are few methods of fixing vessels position by taking bearings of land marks or aids to navigation

1. Cross bearing ( two or more visual bearings)

2. Bearing and Distance(one bearing and distance specified from the same object taken for bearing)

3. Bearing and Soundings

In this practical the first two methods will be used.

1. Position fixing by cross bearings

1. This method of position fixing requires visible landmarks or aids to navigation (at least two but three is better) from which to take bearings.

2. The bearings values are adjusted with variation and deviation, if the given values are not in true .

3. Lines are drawn on the given chart from the landmarks for the given bearing value, by transferring the angular value from compass rose

4. The point of intersect is the position of vessel.

5. The latitude and longitude values corresponding to the particular position of intersect is to be noted, which gives the vessel position.

2. Position Fixing by bearing and distance

  1. Draw a bearing line from the noted land mark on a given chart after adjusting the compass error, if any.
  2. Cut an arc for the given distance from the same land mark taken for bearing measurement by using compass.
  3. The bearing line will intersect on the arc drawn for the given distance at one point.
  4. The intersection point is marked as position of our vessel
  5. Find the latitude and longitude for the point of intersect ie. Vessel’s position.

Observation:

Last modified: Monday, 7 May 2012, 5:04 AM