No sounding depths/details on inland waterway charts

[bcn]

Originally Posted by FreeSpearit

Navionics has an average of 2000 updates per day.

That's a funny quote we see since several years.

Most probably o-charts would be able to claim "more than 1000 updates/day" for oeSENC charts taking into account the updated charts coming from the different Hydrographic Offices and counting the objects involved. And if we then add the NOAA/NGA charts and the free InlandENCs, oh boy...

[Suijin]

The Navionics sonar charts are largely crowd sourced in well trafficked areas. And their accuracy should be taken with a grain of salt. I find them useful in giving me a better sense of the bottom contour but often find the individual soundings to be inaccurate.

To the OP, I believe there is an option to toggle between sonar and non sonar on the iPad app. You may find that useful.

As mentioned relying on charts to provide accurate depth data outside of government channels in unfamiliar areas is unwise. Most of it has not been surveyed since before WW2. If I had a dollar for every time I’ve bumped bottom in 10’ of charted water I could buy a new chart chip lol

[Frank999]

Originally Posted by meridian28

Minimum 9.9 feet on the rivers for barges. No depths shown on the charts

FWIW, the project depth, i.e., the depth that the COE seeks to maintain, is not always maintained. I have bumped bottom in a boat with a 6.5 foot draft inside a 9 ft. channel. I discussed it with a COE engineer, and he said he wasn't surprized.


Also, the project depth is different for different rivers.

[AKA-None]

2000 updates per day over how much area?

[transmitterdan]

Originally Posted by AKA-None

2000 updates per day over how much area?

The planet.

[hellosailor]

"I have bumped bottom in a boat with a 6.5 foot draft inside a 9 ft. channel. I discussed it with a COE engineer, and he said he wasn't surprized."
The world is not a static place. I've been literally 80' under the surface in what was clearly shown as a 40' deep channel. Channels subject to tidal action scour and fill, that's normal. Coastal barrier islands (Fire Island, Miami Beach, so many place in between) routinely move around and sometimes go away entirely.
If you have a static picture of San Francisco taken before the big quake...is it the same today? When parts of the Mississippi River close to shipping traffic because the water has gotten too low, does anyone run out to rechart it? Not really, they know it will change again before they can push out the numbers.
Both ACE and Navionics know the source of the data they are showing. Each can tell you how and whether more data is available from them, and if you're lucky enough to get a cartographer on the phone, they're often quite happy to tell you if there's another source for the data.