Navionics Chart Depth Question

[Mark P]

Folks, I have the Navionics app on the Android phone. When I look at the depth numbers are these "low tide" numbers? I probably should have asked this question long ago

 

[Russell Clifton]

Yes.

 

[bayview]

mean lower low water. Not the lowest is ever gets do web search for details.

 

[caltexflanc]

Time to get a copy of Chapman's Piloting and Seamanship and read it, cover to cover. Take some courses from your local USCG auxiliary or Power Squadron.

 

[kchace]

Time to get a copy of Chapman's Piloting and Seamanship and read it, cover to cover. Take some courses from your local USCG auxiliary or Power Squadron.

 

[tiltrider1]

The depth marked is the amount of water at a zero tide. If your tide is -2 then you have 2 feet less than what is on the chart.

 

[firehoser75]

Except in Canada. We use a different low water datum. We almost never get a negative tide (maybe 2 times per year). Principles are the same however

 

[Rebel112r]

Maybe it’s the settings I have on Navionics because the depths shown are the depths at current tide levels. If you go to a tide station and highlight it, and move the timeline left or right the depth numbers on chart change as you move left or right. At this time we have approx 9 ft of tide, if I move to zero tide the chart depths will reflect this 9 foot change. If you click off of the tide station, the indicated depths go back to the depth which reflects the tide level..For me, I like the feature.

 

[Mark P]

Thank you for the reference to Chapman's - just ordered the book and look forward to reading it.

 

[Pete Meisinger]

My boat draws three and a half feet. Yesterday I motored through an area where the chart showed a depth of two feet. I still showed three feet below my keel.

Lake Michigan is at about three and a half to five feet above the high water datum. Depending on the wind, the rain, and the day.

Charts aren't all that accurate anyway.

pete

 

[Mark P]

Just read Chapman's- great book. I now have a coffee table reference book to impress my friends!

 

[cruiserChick]

There is a feature in the Navionics app that allows you to adjust your readings based on an adjusted water level. So let's say that you live on a dam-controlled lake and the lake is 2 low right now because they dumped water in preparation for a hard rain later in the week. You can go to your app and adjust the water level by 2 feet. Since there is currently no good way for an app to have information like this, Navionics provides you a way to do it yourself. Tides are automatically accounted for since they are predictable.