In the first image there is a significant amount of noise in the sky; foreground is underexposed and blurry. 2nd image: Leaning horizon and also some noise in the sky.
Examine both images at 200% magnfication.
#1 Underexposed, noise.
#2 Noise, artifacts, white balance, horizon is not straight.
Please read these links:
With landscape photos, especially where there is a horizon, make sure you get it level. And then in post-processing, check that it is level, and if not, level it. This is important because visually, a crooked horizon is just bad!! And very noticeable with sea horizons.