Holes in the Deep Ocean

I was sailing in the deep ocean when I saw two (air-)holes in it: Both about 2 x 5 x 4 blocks. One was at the surface and ca. 20 blocks further away and down in the midst of the deep ocean was the other hole.

What I expected to happen was...:
When I sailed along in my boat, there should be no holes in the ocean, obviously.

What actually happened was...:
But there were two holes in the sea, and when I sailed/swam through them I fell (as one would, since one can't sail or swim in the air.

Steps to Reproduce:
1. Find a Deep Ocean Biome
2. Seach for ca. 5 x 2 x 4 blocks worth of air-holes where there should be water. ALSO search deeper down in the ocean.
3. Make holes go away, please.

Thx