People are probably saying things like "where's your subject?" "How is this a portrait?" I am saying, creative use of the challenge. A boat in its natural environment...the water. My only issue is that I wonder if we can actually, honestly say that the boat is interacting with the environment and the environment tells us something about the character of the boat. That being said, I had a hard time telling where the focal point was. Everything is sort of flat.
Portrait, according to Merriam-Webster: a pictorial representation of a person usually showing the face
I can see stretching the definition for an animal, maybe...but not an inanimate object.
Nice image, but I really don't get the sense of portrait with this shot. Portrait ordinarily means a living thing in the picture. Anyway, overall your sat is nice,though the glare in the background is a bit much. Use of maybe a neutral density filter might have cut back on the glare.