Out goofing around yesterday, and found a 23' sailboat high and dry, maybe
15yds from a navigable creek. I'm guessing it could be dragged over the
marsh and into the water, but even with a really high lunar tide, it's going
to take some force. There isn't anything across from it to secure a winch,
and the creek isn't deep enough to get a big boat in to drag it off.

Any idea how I can do this?

Ironically I want to float it to another location and beach it there.