Last time I was out I was down to 1.6 feet
of water on the sounder, engine tilted up, which given that I was miles from home was starting to make me pucker a bit as I wasn't sure if the sandbar was going to get any shallower before I got over it and I'd not crossed it before. As it was I was ok, though I wasn't certain if the tide was rising or falling so I did take a different route on the way home...
I agree that less than 6ft/2m in unfamiliar waters makes me really pay attention and slow right down even if the chart says it is OK.
GJ0KYZ's video is excellent
As somebody who launches off slightly dubious beaches, I also agree that a good poke around at dead low water is well worth doing so you know where the lumpy bits are (& can pick up any prop mangling debris and dispose of it)