I'm starting a new thread so not to hijack the current one
I like the sliding harness concept
, but does using a clip like in your picture mean the strap gets left behind on the dock
Wouldn't it be better to have some sort of a release-able loop for the dock
cleat end? Something like a halyard
shackle with a line to the pin, so you can open the shackle from the boat. You could even have that line go back up to the bow cleat, so the shackle pin gets pulled when the strap slides far enough aft, and the whole assembly comes with the boat. That way, instead of a clip, you could use a regular pulley.
You'd want to keep it reasonably light, as that whole assembly will come swinging against the side of the boat after you've released, but if you're using soft shackles, the halyard
shackle would be the only worry.
It's a bit complicated, but if you're moving slowly enough, then a stuck line or shackle would only make your boat pivot at the end of the finger. Worst case, you could release the shackle release line and the bow-stern harness line and let the whole thing slide away (just keep it out of your prop!).