Thanks guys! I did not try launching my boat yet for the trial -- I wanted to test the waters, get my feet wet, do a dry run, not muddle things on a first outing with a sink or swim attitude, instead tread softly while taking my first steps.......if you know what I mean!
I wanted to be cautious, and definitely, there are many different kinds of mud. This trial was successful, but I did find that the bottom slope was so slight, I'd have to walk a long distance with the boat to find enough depth. In some ways a rapidly sloping shore would be easier, and provide more confidence. If we get more rain, it will also be easier/closer. So I'm going to give it a wait for a couple inches more depth.
(re. normal http linked photos not seen by some browsers.... see
https://www.madmodder.net/index.php/topic,13481.0.html)