The bug that I found was that there's a 2x1.5 vertical gap in the middle of the ocean that has randomly generated whilst I was testing out the new 1.8 pre-release snapshot. The mode of gameplay that I used to test the snapshot was in creative mode, so I do not know if it just affected in this specific mode or in all, the seed that I used for the snapshot was: -930658329
and the coordinates of this bug is (X/Y/Z): 166 / 62 / -332.

There is another bug in the water almost directly below the one breaking the surface