I pulled the Fathers' Day card and got a bunch of time back at the pond yesterday and I ended up learning a lot. I don't think my muck/silt problem is as bad as I had originally thought. Last year I had gone around in my canoe to try to get a sense of the depth and used a tape measure which wasn't all that effective. This time I used a 1" x 8' steel pipe which penetrated the muck layer and allowed me to find the true bottom. I'm still not sure how much muck and loose silt is there, but the pipe did allow me to determine that the pond has a very hard and rocky bottom. Utilizing a combination of the pipe and a tape measure I was able to measure depths of about 4' which are about 6-8' out from the banks and as much as 5'-6" to 6' in the middle. Using my old Sears fiberglass canoe as a work boat, I pulled a bunch of brush from the pond that seemed like it had started on land, drooped into the water and sprouted roots everywhere:

[Linked Image from i.imgur.com]

This photo is looking toward the more silted in end of the pond where runoff from the neighboring fields tends to sheet flow and/or follow a channel into the pond. I removed a bunch of the stuff that was growing IN the water but as you can see on the right and left sides there is still drooping vegetation. I plan on really aggressively working both sides with a chainsaw to get rid of a bunch of that stuff and clean up the banks.

[Linked Image from i.imgur.com]

The far side I'm going to leave alone for now because it is basically a wetland that probably serves to trap silt at that end rather than allowing it to flow into the rest of the pond. I figure one day when I have the $$$ I could rent a machine and scoop it out in a couple of buckets full and enlarge the pond another 10-20'. I just ordered these and a thermometer which will be here this week:

https://shop.naturalwaterscapes.com/muck-remover-pellets-10-lbs/

I plan on using the 1/4 acre dose which is double what I need at about an 1/8 of an acre, but the directions recommend that for older ponds. I'll try to distribute them as evenly as possible which shouldn't be too hard given the size of the pond. I'm also looking at aeration options, but the pond is about 225-250' from the nearest outlet. I figure the best option is a septic aerator pump and a long airline. Hopefully I can make a lot of progress this summer and into the fall. Of course if we have another winter like the last one I'll pretty much be able to work down there year round.