I love the color of the sky and how clear the horizon is. I like how it's different on both ends!
If any, here's a few things that I think you could use to improve it (or similar stuff in the future):
1) I wish I could see more of the foreground. Since you included the rocks separate from the one in the middle, I wish they were bolder/stronger. Try lowering the camera a little bit more, if your tripod can allow it. Otherwise, use a longer focal length to bring the background and subject closer together.
2) If you want the rocks in the middle to stand out more, get closer to them even by only a few steps, and apply what's on #1.
3) I wish I could see more of the sky. It's either you place the horizon at the center, or play with the 1/3 x 2/3 sky-sea ratio until you get better results.
4) Make the shutter speed slower by a few notch to get that "dreamy seascape" you are trying to acquire.
5) A graduated can help you expose better, but it's completely optional especially if you don't have one. You can do this without that. If you have access to Lightroom, you can use the built in tool to simulate that effect. That is, if you're having trouble exposing the foreground elements against the sky.
Good luck and have fun during the golden hour!