Recently I updated the software to 5.69 on my e120 classics and in so doing a a hard reset was required and a number of settings changed. With my simrad ap on my heading on the RM will be showing (i.e.300 degrees), which agrees with my regular compass and ap heading. I'm sure the RM gets the heading from the AP. What is odd is when motoring my COG will be off by 6-8 degrees to these although on a Furuno gps GP37 my COG is the same 300 degrees. Is there a setting on the E120s that I need to change so that COG is the same? Thx
Does it have a M or a T next to your COG? Your COG might have been set in your E120 to true instead of magnetic. Your autopilot is displaying magnetic and the Furuno obviously the same.
Capt J, Will double check but yesterday I went into the menu and both E120 units are set to magnetic so it is strange that COG is so different when moving. Yes everything is set to magnetic that I am aware of. Didn't go into the GP37 menu but the COG on it is right with AP, heading indicator and compass heading. Thanks
COG and vessel heading are seldom the same. The vessel heading is simply the (magnetic or true) direction the vessel is "pointed", and the AP is set to. The COG is determined by the GPS and differs from the magnetic heading because of drift/wind/current/etc. Unless you are operating in calm seas and no wind, the COG and MH should differ.