Chapter 5: Customising theST4000 Plus 37Compass deviation correction (SWING COMPASS)The compass deviation correction option allows you to correct thecompass for deviating magentic fields. The procedure must beperformed as the first item in your initial sea trial, and is described indetail in Chapter 7, Post Installation Procedures.Deviation display (DEVIATION)This screen shows the current deviation value, calculated from thecorrection procedure (Swing Compass). You cannot edit this value.Heading alignment (HDG ALIGN)The heading alignment screen shows the current reported heading.Note: Always check compass alignment after compass deviationcorrection (see ìPost Installation Proceduresî). However, once theinitial correction procedure has been carried out, make any alignmentadjustments as often as you wish, without re-correcting your compass.ï Steer your vessel onto a known heading and check the heading.ï If required, adjust the heading value to match the known value, usingthe -1, +1, -10 and +10 keys.Heading mode (HDG)Select either magnetic or true heading mode. When heading data isdisplayed in normal operation, the screen indicates whether true ormagnetic mode has been selected.Bar selection (RUDD BAR)Select the type of bar graph that is shown at the bottom of the displays.The options are as follows:RUDD BAR: This shows the rudder position. Note that a rudderreference transducer is required for accurateWheel Pilot rudderposition information.STEER BAR: This is the default setting. The bar graph is used asfollows:
