Anyway, here is my exercise on horizon:
1. This shot is approximately divided into two equal parts. The foreground makes the composition not that static. Though it would be good to have the ND gradual filter to make the foreground not that dark. Also, it seemed to me that there was too much of the foreground.
2. For the second shot I came a bit closer. In this picture the foreground and the background seem more balanced.
3. Here I gave all the priority to the blue sky. Because the time when I was taking pictures was just before and just after sundown, the sky was changing all the time. This one was just after sun went down.
The color of the sky was fantastic, and I decided to make a vertical shot of it to stress the contrast of the sky as much as possible.
4. Here I wanted to combine the colors of horizon and pay more attention to the patience of the sea. That is why the sea is taking most of the frame. To stress the patience of the sea even more, I was taking this picture at a longer shutter speed, which is shown in slight waves movement.
5. This is the other variation of the horizon with priority given to the sea. Because I was not very sure about the foreground in the previous picture, I have taken another one, but without shore in the foreground.
The overall conclusion of this exercise is that the position of the horizon is very much dependent on what you want to show in your shot. Is it mostly sea, that you are looking at or the sky that is showing lovely clouds patterns? Or maybe the foreground detail would add something to your shot that would make it look the best. There are plenty of options in this field!