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NOAA vs AquaMap USACE depth charting
Per a discussion over in "Product Announcements", here is a comparison of NOAA ENC charting with AquaMaps's rendition of USACE detailed soundings charts.
This is Aquamap with the USACE survey superimposed:
Where was the tide when those AquaMaps were collected? Is that showing MLW or actual values?
Those are not sourced by AquaMap per se, but are rather overlays from the US Army Corps of Engineers (USACE) sounding studies. AquaMaps takes the public-domain data and constructs overlays to their charts with it. I believe that all depth data is referenced to MLLW, just as the NOAA ENCs are.
For areas like the Chesapeake or the ICW, where shoaling is an ongoing process and shallow depths are a problem, these overlays are a great resource. I only wish they made more of them! If you click on them in AquaMaps, it will tell you when it was done.
Yes, while you were replying I was over reading their website reading more about it.
I've been tempted to sign up and get my depth sensor readings integrated as part of the community readings (understand that's not the USACE stuff). Now that I've gotten a new on-board internet setup (pepwave MBR 5G) it'll be a little easier to get things online.
I really like AquaMap - and I know I'm not using more than a fraction of what it can do.. It is REAL HANDY to have a real chart in your pocket whilst eating in the restaurant 🙂 They also have Explorer charts of the Bahamas, which is another big plus - we got led astray there by Navionics (and NV) when Explorer had the straight scoop.
I've used Navionics user-based charting and it is intermittent - some places it gives you an excellent idea what's there, while in others it can lead you seriously astray. It was amusing to see the result in the Bahamas where literally everybody drives down the same lines between waypoints - micro differences in reported sensor depth or time (tide) make some rather bizarre resultant depth contours! I also had them lie to me in a spot here in the Chesapeake where there is a very narrow dredged channel (Jackson Creek, VA) - since everybody who has been there knows what it is, they get zero data from outside the channel - so it got depicted as being the same depth as the main part of the bay! Fortunately, the edge was sharp enough we just bounced off 🙂
good point regarding lack of data beyond well-traveled routes.
@wkearney99 All you need is a WiFi gateway to send depth data to your smartphone running AquaMap and it will encode depth and store it with your track. You can participate in NOAA's CSB (Crowd Sourced Bathymetry) which in turn is a member of the International Hydrographic Organization. On the website, one can filter for CSB and specifically from Aqua Map and in my case, our boat's name is Little Wing https://www.ncei.noaa.gov/maps/iho_dcdb/
@hartley I use Navionics as well and find in some places, "high precision" but "low accuracy". One neat feature is called Live Sonar where you wifi connect your smartphone to a Vexilar Sonarphone device and it will update your bottom contour right in the Navionics App. I use this primarily to scout out places in my dink before taking the mothership in. https://www.navionics.com/usa/charts/features/sonarchart-live