Hello Marco and welcome to the forum! :-) Here's what I think: Your photo is really nice, and will have fitted in the monthly challenge. However, the white strip of clouds steals a lot of attention from the water. The objective of this challenge is to take something (any object) and shoot it against a similarly colored background to show subtle differences in hue and how appropriate lighting can make things look more interesting despite the lack of a wide color range. If it were a blue ball floating in the water for example, that, in my opinion would be a more acceptable entry. The sky and the water make excellent backgrounds. Feel free to play around with your entry, there are unlimited posibilities (within this given limitation of course hehehe...) Have fun with this months challenge, and we hope to see more of your work here! :-) (*