gps settings true north or mag north

[Volvo]

I do have my GPS/plotter set to magnetic and ust that ""just incase" i ned to use the compass to continue or head abck jhome if it plays up. Mind you i can also plot a course via compass but easier to suss it out offorehand and know which direction to head if plotter plays up.
Likementioned above by SatNav the reason for distance variation between them arks would be due to different datum used and the again can always be a slight variation between one plotter to another.

[SatNav]

1. Yes variations between plotters these days are very minimal and typical (well) less than 10 metres, the biggest issues and causes of most errors are typically "user" error

[ScottB]

I'll put in another vote for magnetic. I usually pull up a waypoint, see its bearing and then use the compass to steer to it rather than following the chart plotter the whole way...

[Lucky Loz]

Personally I love the Highway mode on my Navman.Sooo easy. But could you please explain what you mean about different Datum guys. Sounds like Hokus Pokus.

[TheRealAndy]

Personally I love the Highway mode on my Navman.Sooo easy. But could you please explain what you mean about different Datum guys. Sounds like Hokus Pokus.

A datum, in short is just a point on earth where measurements are made from. The datum changes depending on where you are on the planet and who draws the maps.. Aussie maps are GDA94 (not sure about AHO maritime maps), GPS is WGS84. The difference between the two as far as boaties are concerned is negligible, ie less than 1 metre. Your GPS error will have more error.