True or magnetic North???

[bammylovechops]

Hi,

I have a Flybridge Sealine F34, it has a Raymarine auto-pilot fitted at both helms, one is showing "True North" the other "Mag North". Which one should I use or does it not matter that both are different? I also have a Raymarine E series, not sure which setting that uses!
Your thoughts please.

Mark

 

[pmagowan]

Magnetic north will align with your compass which is handy. True North will align with your paper charts which might be handy if you ever use them.

 

[prv]

...and at the moment, there's very little between the two of them anyway

Pete

 

[alant]

Hi,

I have a Flybridge Sealine F34, it has a Raymarine auto-pilot fitted at both helms, one is showing "True North" the other "Mag North". Which one should I use or does it not matter that both are different? I also have a Raymarine E series, not sure which setting that uses!
Your thoughts please.

Mark

Does it matter, don't you normally just point the boat in the direction required, change to auto & fine adjust so it looks ok. At mobo speeds, not found an owner yet, who worked out a CTS in advance, usually just heading for a waypoint, so which compass setting is in control is somewhat academic, unless in the Grey Navy of course.

 

[Medskipper]

It almost makes no difference to a fast motor cruiser, most skippers can't steer within those tolerances anyway!

 

[bammylovechops]

But with both displays set separately do they not counteract each other, I did notice we were doing a bit of snaking rather than staying in a straight line.

 

[alant]

But with both displays set separately do they not counteract each other, I did notice we were doing a bit of snaking rather than staying in a straight line.

Probably more to do with your autopilot sensitivety setting.
If set on coarse, will make large adjustments & subsequent readjustments, very noticeable as snaking when at speed.

 

[omega2]

One or t'other as stated no real problem, run the plotter head up and you can "see" where you are going.

 

[Lon nan Gruagach]

Arent the devices at the helms just display and remote control of the single autohelm computer, in which case the displayed heading is just that a display, not a control. The computer will read the compass, the displays will read the compass. And, unless you have accurate tide and wind information it only tells which way the boat is pointing, not which way it is going and thats the important bit isnt it?