In the days of sail it was virtually impossible to steer a course accurately to within a degree. As a result the compass was divided into thirty two equal “points”, each 11¼° wide. The four major points, namely north, south, east and west, are referred to as the four cardinal points of the compass. The…
Three figure notation. All bearings and headings (courses) are expressed in three figures. For example: North is expressed as 000°. South is expressed as 180°. North-west is expressed as 045°. Five degrees to the right of north is expressed as 005°. The reason for this is to avoid confusion with any other angular measurement.
So far we have covered the basic definitions and concepts used in nautical navigation. We will now look at a number of simple problems to demonstrate our understanding of these definitions/concepts. This practical assignment assumes that you have access to a physical copy of a nautical chart for the Table Bay and False Bay areas.…
Need for Passage Planning. Just as you would not make a long journey by car without proper planning beforehand, so is it with sea voyages. In fact it is even more essential. Remember there are no roads at sea and the surface of the sea is not smooth and static. There are also more dangers…
Navigational charts are produced by the Hydrographic authorities of a country. In our case the authority is the SA Navy Hydrographic Office. The headquarters of the hydrographer is situated at Silvermine in Cape Town. The charts are compiled and printed according to international standards and conventions and are therefore usable by any seafaring nation in…
East and West. The earth is a sphere which rotates about its own axis. The direction towards which it rotates is “East” and the opposite direction is “West”. See the sketch below. North and South. The axis of the earth has two poles. The pole to one’s left when facing east is the “North” pole…
Besides the navigation equipment used by the navigator, the latter also requires certain instruments, publications and stationery to assist him in the performance of his duties. The items include the following: Charts. Just as you would require roadmaps to plan and monitor your holiday, so does the navigator when planning a voyage. He would start…
Though the number and types of navigation equipment may differ from ship to ship, virtually all ships will carry the following: At least one gyro compass (the primary compass). A magnetic compass (the auxiliary back-up compass). At least one radar (operating in the 30 GHz frequency band). Ideally it should have two, one operating in…
Although all deck officers are navigators it is usually the practice to appoint one of the officers as “the navigator” who is responsible for planning and overseeing the navigation function aboard a seagoing vessel. Broadly, his duties/responsibilities are the following: The preparation and planning of the safest and most economical passage between the ports of…
Navigation can be defined as the process followed in getting a vessel from one geographical point to another in the safest and most economical way. Whilst the methods used are based upon sound scientific and mathematical principles, their efficient execution is based upon the experience and skill of the navigator. Being a land based creature,…
