Symbols in
charts are defined by the issuing Authorities, based in standards from IMO, in case of ECDIS, there are different symbols from raster
charts and vector ones.
in ECDIS displays there is one option to show the symbols "like" tradicional paper charts (raster).
from one side it understood that symbols should be different in order differentiate both charts quickly.
bear in mind that in raster charts you could not query on any information of the chart because it's a simple scanned image, they are what you just see in the
screen and nothing else, rather than the vector ones that symbols are information in their definition.