I sail the Columbia River. I would like to find a chart plotter that
has chart tables that cover the tidal influence - which runs all the
way to Portland Oregon. I don't NEED it I WANT it.

I currently have a Garmin GPSMAP 492C. The last tide station it
displays in Knappa Slough, Oregon side. PC based programs seem to
have many more prediction points - as far east a Bonneville Dam.

Garmin has responded to questions but only with the answer that "the
eastern most tide station and prediction is Knappa Slough."

Any input?