Mark P
Senior Member
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
Navionics Chart Depth Question
- Thread starter Mark P
- Start date
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If you have answers, please help by responding to the unanswered posts.
If you have answers, please help by responding to the unanswered posts.
Russell Clifton
Guru
Yes.
caltexflanc
Guru
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
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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
Guru
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- former owner of "Pilitak"
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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
Guru
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.
OP
OP
Mark P
Senior Member
Thank you for the reference to Chapman's - just ordered the book and look forward to reading it.
PM
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- Best Alternative
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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
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
OP
OP
Mark P
Senior Member
Just read Chapman's- great book. I now have a coffee table reference book to impress my friends!
cruiserChick
Senior Member
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.
