PNW Current Atlas 4+

Great App, times seem to be off

Update: Thank you for the quick response. We do find the app very useful in seeing current trends where there is no Navionics current data.

The currents seem to be off by an amount of time. (1hr late?). Navionics is correct for the points they report out on, comparing to exact places.

Developer Response ,

Yes the app is fully DST aware. Internally everything is in GMT/UTC and converted to the timezone your device has set, i.e. your local time.

Current atlas charts are not appropriate for timing current passes like Dodd, Gabriola, Active Pass, etc. As an atlas, charts were never designed for predicting restricted areas but rather large scale patterns. In fact the closest current “arrow” on charts near a pass is likely outside the actual pass as defined by a current and tide table. Always use an official current table for transiting passes.

As for the chart time spacing between pages, there is no standardized length of time between chart pages because the time duration between each low and high tide varies for each tide cycle. There are a set number of charts for each cycle and the time is divided to space out the charts to match the cycle duration.

Hope this helps. And thanks for the info on the support page not working. We’ll get it fix asap.

Great Resource

At one point I was using the app and I found what I thought was an error since there was a disagreement between the paper current atlas and the app. I recorded the time and the referenced pages and reached out to the author of the app. He wrote several emails explaining the additional algorithms used for the app, and how since the paper atlas is by hour is often doesn’t show small reversals and other small changes. He walked me thru the data used and how his app presents the analysis. I won’t stop referencing the paper current atlas but I will use this app as well. Randall

Brilliant

I sail a small boat in these waters, and depend on the Canadian current atlas for every trip. This implementation is fantastic. And since you have to buy an update to the printed atlas every year for $20, the once off price for the app is well worth it. The app also lets you scan the currents hourly, instead of paging through the printed guide. Very impressive.