@Tedd Lay out a simple route. This one is for a passage through Deception Passage, Using OpenCPN with tide currents visual.
I lay out the route than click on the tidal sites to see what the tide is doing. The link provides the calculated tide currents at various time point. On this stretch I would examine the tidal information at the critical location.
Under the bridge.
I can scroll up and down to decide when is the best time to run through.
The DeepZoom and Coastal Explorer provided further extension of this idea in that the software lets you adjust your departure time for the route then showing the currents when you are supposed to cross the passage. CE also had a rudimentary calculation of cumulated route passage time generating an ETA. When I worked with it, there was a lack of accuracy.
I took their current information and plugged it into a spread sheet and I was able to resolve the issue. I shared it with them but they were too busy with other programming to fix this glitch.
This whole world of routing using computers is an evolving process. It is always best to check your work before you head out.
I do like the GRIB function of OpenCPN. Just would like to more easily apply it. Currently working with LuckGrib on David's Cross Atlantic sailing and really like the results. Will be working with it hear in the PacificNW over the next couple of weeks.