4th pic superb... just imagine, what if there was a sampan or a boat etc. at the right side of the frame? Gud effort..
3rd. pic ... u have placed the horizon right in the middle of the frame.. it has divided your shot into 2 equal parts.. The Rule of thirds suggests that the horizon should be at the lower or upper third of the frame. The horizon at the centre will only work for reflection or symmetrical shots..
2nd pic.. very well executed.. gud use of the rocks as the foreground detail.. it will be better if u placed the rocks more towards the left...
Finally the 1st pic... gud use of the wide angle lens. Helps to highlight the beautiful sky.. u should have placed the horizon at the lower third.. coz, the foreground is a bit too dark..