Lake bottom caracteristics.

[bottomfeeder]

I was diving a lake in the Elk River area (Twin Lakes) and noticed that the bottom on the south side was very mucky (couldn't touch bottom with my hand) but got better as I got to the east side (maybe 1/2 inch deep). Is there any rhyme or reason to this in comparison to other lakes?  ??? ex. moss growing on the north side of the tree.

Thanks for your help. This will help me have a better dive plan in a lake.