Warning for Navionics Users

[Roger Long]

A couple of people are still checking it out. I’m not too familiar with the program so further investigation and comments welcome.



Navionics seems to have changed the displayed chart soundings so that they are corrected to the state of tide at time of viewing. Convenient maybe for the boater with minimum navigational proficiency that the program seems increasingly aimed at but a potentially dangerous trap. If you plan a route ahead of time (always good practice) at high tide, you could have a surprise if you arrive six hours later. How does auto routing know when you plan to leave? A friend who primarily uses the program has discovered that depths in places that don’t change, such as behind locks, have their depths changed according to the nearest tide station which may be on the other side of the lock.



If there is a notice somewhere that Garmin has changed the established nautical practice of chart soundings always being MMLW, it’s hidden enough that I haven’t seen it.

 

[ScottC]

This is disturbing, indeed. I hadn't heard about such a change. Thanks for the alert on this possible issue.
I'm not near my boat right now, so can't easily check this further. I would hope there might be some way to change this via a user preference setting!?!

 

[Alaskaflyer]

I am (currently) only an app user so I don’t know how this is working in Garmin hardware. But I just noticed it the other day when looking at something on my iPad and have been playing with it.

What I think would be most useful is not so much the real time soundings - I share your concern - but watching the soundings change while scrolling through future tide cycles, instead of having to do the math in your head In other words, you can select the nearest tide station and bring the tide waveform up at the bottom of the screen, scroll over to a terrain feature like an anchorage, and then scroll through the tide waveform and see the depth contours change back and forth on your screen.

I do know that you can disable the feature - in iOS it is a toggle button in the map layer pop up screen.

 

[psneeld]

Like letting anyone else think for you....AI is no different...always take it as a suggestion.

Until it's real time, totally integrated....it can never be more than an advisor.

 

[Hippocampus]

Run navionics as a backup on a IPad. There’s a setting “Water Level Correction” on the menu. If I turn this off do I get mean low water only?

 

[Alaskaflyer]

Hmmm. That toggle doesn’t do anything for me. I believe this new feature has the ability to utilize real time (compatible) sonar data inputs and adjust depths based on that data, so maybe that controls some aspect of that.

I’ll backtrack and say I’m not so sure that this can be disabled on the app, I thought I did but I see tidal changes still manifesting in the bathymetry numbers and shading.

 

[Roger Long]

Reported in another forum that someone has contacted Navionics, they are aware of the problem, and it will be fixed in a future update.

 

[ScottC]

Hmmm. I wonder if this might have something to do with Navionics Sonar charts. They come with the Platinum Plus charts that I normally buy, but I try not to use them, as Navionics indicates they are ”not for navigation.” I am frustrated that the sonar chart, without explanation sometimes becomes the default when I turn my plotter on. Certainly an annoyance.

 

[ScottC]

Oh. I see Roger supplied the answer while I was tapping away on my phone for the previous post. Thank you, Roger!

 

[Jeff F]

I use the app on Android and noticed this a few months ago. It's toggled on by default when tide station data is displayed.

I found it a bit disconcerting at first, and it took some experimentation to get used to the feature. But since then I've found it really useful, mostly for route planning.

 

[diver dave]

Yeah, this feature caught me last Aug. after a 15 hour ocean run, We needed sleep. Tucked behind a small island with 10’ on the Navionics chart and 7’ on the sounder. Woke up hours later, stuck. Boat made to sit on the skegs, but annoying. Somehow, Navionics set to +5 feet?

 

[Blissboat]

Yeah, this feature caught me last Aug. after a 15 hour ocean run, We needed sleep. Tucked behind a small island with 10’ on the Navionics chart and 7’ on the sounder. Woke up hours later, stuck. Boat made to sit on the skegs, but annoying. Somehow, Navionics set to +5 feet?

Annoying is right. I am perfectly capable, all by myself, of anchoring where I ought not to on a falling tide. I have no need for a charting app to help me wake up unexpectedly on the hard, thank you very much.

 

[Roger Long]

I think it’s fixed. This morning, I can not reproduce anything I and others were seeing yesterday. Unless a tide chart display is shown on my phone screen, all soundings and depth shading will be MMLW. If the tide station is shown in the display, the soundings and shading will change with the setting of the slider. This is a cool and useful feature.

I brought up a tide station in Maine where tides change fast, turned it off by clicking the chart, and then watched to see if soundings and shading changed over time. They didn’t. Just before doing this, I updated my charts. I think Garmin may push out bug fixes with their chart updates. I also changed the depths displayed with the tide slider and they went back to the proper values immediately upon turning off the tide station display by clicking the chart.

Can anyone out there make the program change depths and shading from MMLW if a tide station is not active and displayed? If so please let us know.

 

[Alaskaflyer]

App user here, not MFD, but yes, I can also see the changes you mention this morning. Still cannot see any functional use for “water level correction” toggle - which may only be applicable if you are recording your own SonarChart Live data using your sounder.

 

[Simi 60]

And this is why Navionics is a firm 4th backup on our nav gear.

Far to many WTF issues even when travelling the well travelled path.

 

[diver dave]

And this is why Navionics is a firm 4th backup on our nav gear.

Far to many WTF issues even when travelling the well travelled path.

Only one with enough detail off the beaten path. I can provide one glaring example, actually i’d like to see some others at this spot.

 

[Simi 60]

Only one with enough detail off the beaten path. I can provide one glaring example, actually i’d like to see some others at this spot.

For sure there are spots where it has additional detail and for that reason we use pre loaded geo-referenced KAP files using OpenCPN/sat2chart/sasplanet

That way at the click of a mouse I have CMap, CM93, Navionics and a satellite overlay as well

It's more the routing I have an issue with.
If believing that, it sends us on routes that would end with loss of boat and possibly life.