richg99 said:
Just read the review and it appears that it only offers the ENCs. I should point out that the reviewer is incorrect in his assertion that the vector charts are lower quality or have less information; they actually have far more information. If you're a USCG inspected vessel and you want to go paperless (i.e. not use official paper charts and just use electronic navigation systems), then you have to use an ECDIS (Electronic Chart Display and Information System) with the ENCs.
I'm going to geek out over nautical charts now, so feel free to disregard (I used to work for NOAA making charts):
The raster chart is essentially just a picture of the paper chart that is geo-referenced. A "dumb" chart as it were. As you zoom in the image gets bigger and as you zoom out, the image gets smaller. There is also no additional information with the chart.
The ENC or vector chart, by contrast, is a smart chart and is far more interactive. Point features (like rocks, wrecks, and obstructions) and lines are individual features that are select-able with lots of information on particular features. With a vector chart, as you zoom in and out, everything scales appropriately (e.g. if you zoom into an area the soundings can get denser and more features can be displayed that would be confusing and jumbled at a smaller scale). You can turn on and off labels or other features, display specific depth curves (e.g. if you draw 3-ft you could highlight the 3-ft depth curve to know to say outside that line), issue warnings if you cross into an area you designated as off limits, and a host of other cool features. I don't know if the Navionics App allows you to do any of this since I haven't played with it, but the functionality is there in the ENC.
You can also read more about the differences at the NOAA website (
https://www.nauticalcharts.noaa.gov/mcd/learn_diffRNC_ENC.html).