changes quite a bit and there are shoals to deal with. The following is a good web link for up to date information that is not from the US governemnt but from actual cruisers. Of course it's not official<g>.
Of note is that there was money
appropriated for ICW
dredging, but so far we don't know when. Dismal Swamp Canal was totally dredged last year after Isabell and is in good shape other places have problems.
Bob has a few guides for the ICW, Great Circle Route
and some other canals. They are not very fancy but loaded with good information you would want to know about.
The web site does have good shoal information and bridge changes you might find hard to get from other sources. It is maintained regularly too.
The guide has a lot more.