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

1.
chiaro come il fango, incomprensibile
very difficult to understand; not clear at all
:
•
His explanation of the new policy was as clear as mud.
La sua spiegazione della nuova politica era chiara come il fango.
•
The instructions for assembling the furniture were as clear as mud, so I had to guess.
Le istruzioni per montare i mobili erano chiare come il fango, quindi ho dovuto tirare a indovinare.