I sure wish people would stop using SBRs stupid experiment in the water as proof. 6 miles is not far enough to see much curve. At that close of a distance, the Earth would have not dropped very much; and definitely not enough to see at 18 inches above the water, with the naked eye, unless some rare conditions exist. This does not prove the Earth is flat. I just means that you have to be much farther than 6 miles to see much of the curves affect.
Plus, the water was moving, so it was obviously slanted, not straight.