That's ingenious, you can lift yourself out as and when you please
I'm considering one of those Heatherwick rolling bridges installed on the well deck, then you can just drop mud weights in the middle of the canal, roll down the bridge and off you go. It will need a remote control so you can retract it once ashore, and probably advisable to check batteries on same before leaving/arriving.
You can then leave the boat out of reach of miscreants for as long as you like. I can foresee no possible downside