I had looked into those bags awhile back, if I recall, mine would require 5 bags to float/raise the boat , and each bag was something like $500 each.. But even if I had them, I'm don't think it would benefit this situation..
With all the suggestions of sleds and greased slides in mind, I discussed those post with Edwin and Jay, but neither of them agree it's the way to go. Nevertheless, with those suggestions in mind, I examined the area again, walking from the boat to the halfway point the marsh today again at high tide (7.1ft), with the water to my knees.. With little exception, my feet never sank into the mud - point being that the mud does not seem to be deep, two inches at the most. I had solid footing the entire span, so to me it seems a sled would hinder more than help. Sleds on the other hand seems more reasonable (in my mind anyway).
I'm also speculating that if the mud is only a couple inches deep, it would more likely serve as a slippery surface, then it would to cause suction. If I can just get it off the hill, then perhaps the anchor/comealong might then be enough to slide it cross the muddy marsh.
Is there a flaw with reasoning?