December 8, 2020

The fix

The position obtained from the intersection of two or more position lines obtained at approximately the same time is called a fix. The term fix can only be applied to a position obtained from the observation of terrestrial objects. It is shown on the chart as a dot surrounded by […]
December 8, 2020

The observed position and dead reckoning position (DR)

The observed position. The position obtained by the intersection of two or more position lines obtained from the observation of heavenly bodies is known as the observed position. It is shown on the chart as a dot surrounded by a circle, with “Obs” and the time written next to it. […]
December 8, 2020

Ship’s track and estimated position (EP)

Ship’s track. The ship’s course line or “track” is a straight line drawn on a chart in the direction of it’s course. It has arrow heads pointing in the direction of the course and the course is written in along the track. The speed of the vessel is written in […]
December 8, 2020

Taking bearings and visual bearings of terrestrial objects

Taking bearings. Bearings are taken using the azimuth circle fitted to the compass repeater. It is specially designed so that you can observe the object through a metal sighting V on top of a glass prism and the graduations on the compass card through the glass prism at the same […]
December 8, 2020

Cocked hat

Cocked hat. When three or more bearings are taken from a moving ship, the resulting position lines will not as a rule meet in a point, but form a triangle. This triangle is known as a cocked hat. The name “cocked hat” probably refers to the type of hat worn […]