Martin, A cliché isn't necessarily a copy of someone else's work. The people in this thread who have pointed out the problem all have seen probably at least a hundred shots of pilings leading into the sea. I know I have. I've seen better ones than yours (from my friend, Cole Thompson) and I've seen many, many that are a lot worse. As far as copying someone else's work is concerned, don't sweat it. I think it was Picasso who said: "Bad artists borrow; great artists steal." Yes, you've developed what's probably a recognizable style, though so far most of your posts have been a single tree in a barren setting. That's not a "style." It's repetition.
Don't misunderstand what I'm saying. The work of yours I've seen is excellent. I suspect we'd all like to see more of it. I know I would -- especially the kind of street work I just commented on in another thread. But if you post on User Critiques you usually can expect criticism that doesn't beat around the bush. You're good enough that that shouldn't bother you.