All three of these shots are great in their own right.
Each one uses different compositional elements but each accomplished exactly what was asked from you for this assignment.
I’m really impressed with your work, but I’d like to talk about little details in each shot that I want you to be aware of.
In your first shot (which is my favorite), you’ve managed to simplify a very large piece of space which I’m really impressed with. Everything from the placement of the boat to the color palette is correct from a technical standpoint.
The only issue I want to draw your attention to in this photograph is the interaction between layers. Notice how the top of the subject’s head slightly breaks up the horizon line in the background? It’s not wrong what you’ve done, but there is such a sharp distinction in layers in this shot that I think you should have considered raising your camera slightly so the girl’s head fell below the horizon line and only had the water behind the outline of her head.
The second photograph is great as well. It is a little more simplified and the composition is a little different but it’s a really strong photograph that not only abides by the rule of thirds but also contains a great sense of depth, color control and texture. Great work.
The last shot is different because it’s equally as chaotic as your first shot, but the depth is much different. The objects are closer to the foreground and shapes play a much more prominent role than in your first photograph. My only issue with this photograph is you need to be aware of where you cut off your subject’s body parts. Often “amputation” is inevitable and necessary in many circumstances. In fact, it’s used to enhance a photograph when used wisely. However, as a general rule of thumb, try to stay away from amputating your subject at their limbs. When the frame of a photography cuts off your subject by their ankles, wrists or necks, for example, it’s looks a bit awkward.
Other than that, great work on all of these photographs!