For starters, one is monochrome and the other is in color. By using a color filter (most likely in post) the gray tonal values of the different colored water and sky can be matched.
But there's sand and rocks at their start. Where did they go? Were they edited out?
Difference in perspective by shooting from a different position (closer) with a different focal length (wider) and a higher tide.
Also, how does one achieve the effect where the horizon is completely gone and the ground and sky turn into one? How are there no reflections at all?
Difference in atmospheric and surface conditions. The fog has rolled in, the tide is higher, and the water is calmer. The long exposure evens out any ripples in the water by capturing them as they cross the entire frame.