Is it possible to use an image or a CSS gradient for filling of water areas in Google Maps?

I'm currently working on some project and need to implement the next design to a Google Map.

I didn't manage to find any clue to answering of this question in Google Maps style reference - https://developers.google.com/maps/documentation/javascript/style-reference

So, I'm wondreing - is it possible at all (using only API)?

Or some hack is needed? I've thought, for example, about making of water areas transparent and placing the dotted image behind the map.

Thanks in advance!