[bobetter]

On the outside of the turn the same rule would apply - half intersecting angle. See it as the green line continues on the other side of the WP.

I find that for example when creating a route to navigate along a coast with few obstacles (mostly to be able to see remaing distance and ETA and not so much to navigate after), "half intersecting angle" would be much more useful than a circle since the waypoints can safely be passed at rather large distance, and making the circle larger to compensate for this would make it arrive to the WP too early.

I'm not suggesting that MacENC/GPSNavX default behavior should change, I'm just suggesting this alternate behavior for WP arrival/WP passed as an option.

I think I'm starting to get your general idea but I'm not sure that I see the practicality of it over existing standard practice. If you can't keep the course you've laid out, why don't you just move the WP such that you can? If the goal is get accurate ETA data, a LOP (line of position-your "green line") won't accomplish that.

BTW, have you experimented with the SailTimer function?