b393capt wrote:
Kees Verruijt wrote:
The Tack button will tell you what your course will be when you tack and
sail at the same wind angle.

Example: you sail close hauled on port tack, and there's a cliff you
need to clear when you tack. You wait with tacking until the bearing to
the cliff is "past" the tack heading the system predicts you will be
able to attain.

Is this a basic calculation (e.g. it expects the boat to have
symetrical performance on each tack), or does it do something fancy
such as take into account the direction & speed of water current, the
average wind direction for x minutes, etc ?


AFAIK it's quite basic. Instantaneous calculation based on boat speed
(from log, not GPS), course from heading sensor and current wind angle.

--
Kees