I am sure this has been covered before, but are the electronic compass and altimeter necessary?
It seems to me that if you are going to a known point (point B ) from point A the gps will tell you the bearing of point B in relation to you. Then, if you just start walking, it will detect your movement and give you an arrow to go to get to point be even if you start walking in exactly the wrong direction.
Maybe I am missing something and ya'll can fill me in on what I am missing.
See ya later,
CenTex