(as) clear as mud
US /əz klɪr əz mʌd/
UK /əz klɪr əz mʌd/

1.
jasne jak błoto, niezrozumiałe
very difficult to understand; not clear at all
:
•
His explanation of the new policy was as clear as mud.
Jego wyjaśnienie nowej polityki było jasne jak błoto.
•
The instructions for assembling the furniture were as clear as mud, so I had to guess.
Instrukcje montażu mebli były jasne jak błoto, więc musiałem zgadywać.