Insight charts symbology

[Ziggy]

Last summer I bought a B&G Vulcan 7R MFD with 3G radar package. My primary motivation was to replace a defunct radar. The MFD is quite nice too--bright screen and good resolution. I kept my 12 year old Garmin chart plotter, so I'm not dependent on the Vulcan for navigation, but it's a backup and I think the B&G sailing features have potential.

However, the package came with preloaded Insight charts, which appear to be crap. I'm not sure where the bathymetry comes from, but it does not appear to be related to what's shown on the NOAA charts. The symbology is another mystery. For example, does anyone know what a square with blue wavy lines is supposed to mean? I might have guessed it indicates a tide rip, but based on the location it seems be a shoal or a ledge.

Below are some screenshots from 1) Vulcan Insight chart display; 2) NOAA vector chart of the same area; 3) NOAA raster chart of the same area. The blue wavy lines on the insight chart are the only indication of the Old Ciley Ledge. There is no hint of the 2 foot spot, clearly shown on both of the NOAA charts. And the depths appear to be completely made up.


Are the Navionics charts any better?