It's beyond challenging--I think it requires guess-and-check! I can't see any way to logically proceed. Anybody want to give a hint?

R1/c2, 10-12
r14/c5-11

c1/r2, 9-12
c13/r2-4,7-12.

Hints are wrong, r1 C12 and C13 r2 are not possible, you need 3 in a row in that corner.

Hints are corret.

Hints are correct, but not enough. You'll also need:
C11/R8-12
C3/R10-12
C4/R7-9

Still - a bad puzzle, bad picture and not solvable without guessing. What a shame!

Hints by rudi and teesea help a lot.

Thanks Rudi and Teesea!!

Thanks for hints, but I dont understand how to put that.

Dear Cucayo.
C= column
R= row.

C= top to bottom
R= left to right.

This isn't a challenge, it's guesswork.
How puzzles which clearly were never even checked for logic ever get more than half a star will forever elude me.

The amount of hints you need to proceed with this puzzle, then it's already nearly done! ;-)

Terrible.

Teesea's hints plus C11/R12 from Rudi was enough to get it done. Thank you.

I see a face but it looks nothing like a mermaid.