When using a GPS in leg mode going to the IAF for a procedure turn, when you
switch it to OBS mode, don't you loose your navigation (except for the
moving map)? You don't want to wait too long to switch to OBS, or else it
may sequence to the next waypoint when you get to the IAF, but the sooner
you do it, the sooner your navigating with just the moving map, aren't you?