I was not too sure on what to submit for this "water" subject. I just returned from a trip in Iceland, so I had plenty of photos fitting to the topic (even if the water was mostly frozen). I hesitated in submitting a photo of a waterfall which certainly has been photographed a thousand times before. I finally ended up with that long time exposure (a few seconds) of the waves running around the pebbles on a black sandy beach.
As for the topic of the May Challenge, I have not fully made my mind yet. One topic fitting to the season would be flowers, but then, it requires macro lenses or at least lenses with good closeup capabilities which might reduce a bit the number of entries. Another topic would be architecture, building, house, bridge,... whatever could fit the topic.