LEAVING PORT - In a harbor, the largest scale chart should be used for accuracy and detail. The dead reckoning should be started as soon as the vessel gets on the first course. If the track has not been plotted in advance, the dead reckoning is run ahead a short distance. The predicted time of the next turn, or passing the next aid to navigation is logged. Predicted times of arrival at various points are important in avoiding dangerous situations. It is good practice to use all available information. A good position should be maintained at all times. Fog may set in and without warning obscuring landmarks before a round of bearings can be taken. Lights should be identified by their characteristics. At a distance, the color and shape of buoys may not be seen. Sometimes a sailboat can be mistaken for a buoy. Buoys may be out of position or have been removed. Bearings and ranges on fixed objects are better than on floating ones may not remain at fixed points. Soundings should be taken continuously in shoal water. It is good practice to check the compass and radar when ever you get a chance, as when on a range or passing between two headlands. Ranges are great for checking position or keeping on the desired track.
Once you are outside the harbor, if your course is parallel with the coast you can use landmarks and aids to navigation.
Taking departure - When a vessel reaches the open sea and is about to leave the land astern, a last accurate position is taken by means of landmarks. This is called taking departure. It marks the end of piloting and the beginnig of the next phase of the navigation. The work of the navigator becomes less hurried and fixes are obtained less frequently. Soundings become of less interest. The position may be transferred from the chart to a plotting sheet if that is the rule for your ship. Courses and speeds will be maintained over long periods. The sea routine begins. Even if the vessel is to follow the coast, it does so at such a distance that danger is some distance away.
