Looking at a nautical chart, the Franks Tract "island" is mostly 5-7 feet deep. I've always stayed on the east side in the Old River channel, or right along Bethel. The charted depth should mean the middle is full of Egeria (that nasty water weed). The NW "corner" is indicated 1-3 feet deep. There have been times when I've wanted to cut across but always go around as I'm not sure what to expect (weeds or depth/snags). All those flooded "islands" scare the crap out of me.
So, you longtime south Delta peeps, is Franks Tract one of those "need to follow someone that knows" kind of deals? .... or just GO AROUND?!