3 fireballs moved slowly along the beach, then accelerated and flew straight up into the night sky and disappeared.
I was walking on the beach in a remote section near the Orange River inlet.
It was after dark and the tide was low.
I looked out to sea where the breakers were visible in the Moon.
It was then that I saw the fireballs, lined up in a row parallel to the breakers.
They were the size of a house, each moving very slow along the beach.
As the first fireball reached a point, it accelerated rapidly, left to right, and moved 90 degrees up, into the night sky.
As each of the other 2 fireballs reached this approximate location, they, too, accelerated rapidly and moved 90° up into the night sky and disappeared, growing smaller and smaller until I couldn't see them.
Hard to judge speed, but I would guess hundreds of miles per hour once they started to move up into the night sky.
I was frightened and turned to head back to my house and literally bumped into a strange man standing on the beach.
He didn't look at me, just stared at the fireballs.
Said in a detached way:
ball lightning, it was ball lightning.
I ran home and have never forgotten that vision.