This would be a pretty enough picture, but the two silhouetted figures add so much to what would otherwise be yet another picture of a sunset and time-lapse water movement. Well seen.
It is the two lone people in the distance that is the cherry on the top for this shot; they are small in comparison to the majesty of the sunset that the idea invoked is that we are but a small part of the universe. Lovely colors and hues in the sky and sea.
What a cool sky! The placement of the rock in the lower right is good and my eyes are also drawn to the people and building on the horison. I do however wish the shadows had some detail in them. I understand you were probably going for the silhouette look... but thats just me