NavList:

   

Reply

All small boats still use magnetic compasses to steer. Typically this
is a binacle compass at the steering position and an electronic
compass to feed the heading to the autopilot. GPS is only accurate to
a few m so it cannot provide the heading on a time scale required to
steer, but it can give a very reliable True course that has been
steered. Accelerometers and inertial navigation can help of course and
they are used in land and air vehicle navigation systems to
interpolate GPS fixes. Modern high end boat autopilots also have
accelerometers, but I dont know they have a system that works without
a magnetic compass yet.How necessary it is to no the relation between
magnetic and true however is not so clear given GPS, one only needs to
go 100m before you have it calibrated! All it needs to be is
approximately uniform.
On Mon, 25 Feb 2019 at 04:47, David C  wrote:
>
> Is the magnetic compass used today or is it of theoretical/histrorical 
interest only. I believe that in a moving vehicle GNSS can give the track and 
surely that is what matters, not heading.
>
> 

   

Reply