Debussy had an affection for the sea - the cost more than the middle ocean. I traveled to a couple of his favorite places to find his "inspirations" and there were there; all neat and bobbing in harbors and and near by beaches.
Dock areas are something pretty linear in the morning light and calm water. After too many episodes of Joy of Painting, one tends to note the pure vertical lines that reflect out to a soft blur, sometimes it being hard to find the spot where reality ends and reflection begins. Long time back in an art history class we talked about this and I had to give a paper on the musical equals to the painted picture. I remember noting a couple things, not the least was that painters could easily compose a painting that went from one to the other and in essence use multiple techniques in one work; if this photo were a painting it wouldn't be considered bad technique to go from the clarity to the blurr - its just the way it is when it is seen - and that the overall is the work; not the technique.
In music - in composition of music - it is that fight to keep your compositional technique "pure" to one style or stylistic method that is the trick. At the turn of the last century there was a battle in technique between those who wrote music of reflections and those who composed like the docks - all vertical and clearly etched.
Two French composers, Ravel and Debussy wrote in both styles but the most successful pieces from each are clearly shoreline and reflection figurative speaking. See if you can spot which is who or who is which.