Chapter 3: Advanced Operation 21SafetyPassage making in Track mode removes the chores of compensatingfor wind and tidal drift, and will aid precise navigation. However, it isimportant to maintain an accurate log with regular plots.Position confirmation at the start of a passageAt the start of a passage you must always confirm the fix given by theposition transducer, using an easily identifiable fixed object. Check forfixed positional errors and compensate for them.Verifying computed positionsï Verify the computed position with a dead reckoned position,calculated from the average course steered and the distance logged.Plot frequencyï In open water, plots should be at least hourly.ï In confined waters, or when potential hazards are near, plots shouldbe more frequent.ï Local variations in radio signal quality, and changes in the tidalstream, will produce deviations from the desired track.Setting waypointsï When setting waypoints, remember that deviations will occur.ï Thoroughly check along each track.ï Check up to 0.5†nm each side of the track to ensure that there are nohazards within the zone.GeneralThe use of Track mode will enable accurate track keeping even incomplex navigational situations. However, it cannot remove theresponsibility of the skipper to ensure the safety of his vessel at all timesby careful navigation and frequent position checks.3.2 Operation in Vane mode (WindTrim)Vane mode, also known as WindTrim, allows the ST4000 Plus tomaintain a course relative to an apparent wind angle. It uses wind trimto eliminate the effects of turbulence and short term wind variations,
