If your shore line does not get solid and you do decide to use rock, probably need something fairly coarse for the first layer to keep it from just sinking into the mud. Then top it off with finer stuff that is easier to walk on.
Pictures of our shore line linked in our member introduction thread.
Pictures of pond shoreline at bottom of written text These shores have 2-3" crushed lateral rock as the base (rock used for septic system lateral lines) and AB3 for the topping (1" rock with fines and various sizes in between).
I also ran the larger rock about 2' down into the water to stop shoreline erosion from wave action. We get a lot of wind at times.
One way of maybe helping your problem.
