I like the movement in this and the direction. Just two suggestions:
Watch your colour balance. I'm not saying don't use the colours only that colours work by the way they contrast each other. If you have an overall cast, or varying amounts of the same colour through the image, then you tend to dull that contrast. All I've done is remove some of the background colour from the foreground, see how the colours stand out just because they now contrast more with the background.
The other is don't rely on placing the horizon by thirds, it only works when you have a rhythm of thirds through the whole image. Look at the relative areas each element occupies and also look at the distance each object is from the frame and each other. You add this grid when you add the frame so how the elements fit within this frame is very important. Think of polka dots, they are a rhythmic pattern but only become symmetrical within your image when you line the frame up so the dots on the left and right/top and bottom have the same visual relationship to the frame, their relationship to each other is not changed. Think of an image like yours in the same way. Look at the elements in terms of their distance from the frame and their distance from each other. We see and judge distance by regular intervals, you've added the grid for this when you added the frame (you placed the horizon on one of your grid lines ). Just line the elements up with this in mind rather than just placing the horizon at thirds. The inward movement of water actually sweeps your eye out, the object and elements aid so make the passage smooth rather than unequal jumps. There are many solutions.
Good advice Tim. I don't think I actually used the grid lol I never have it on in live display. But I guess it's more of a reaction and getting the rock I was standing on but I could have moved the frame up I think.
Agree on the colour I can't notice it on my phone but yeah I know what you mean