Simone Gutsche was bathing in the waters off Florida’s Cape Canaveral when the monstrous beast appeared to swim behind her.
Terrified onlookers desperately tried to hail Simone out of the water.
But she thought the worried wavers were merely being friendly and waved back at them.
Lucky Simone, 34, said: “There was nobody in the water, not many people were around.
I found the emptiness beautiful.
“A couple waved to me full of excitement. Out of friendliness, I waved back.”
Terrifying pictures show the moment the five metre-long shark passed behind Simone, its menacing fin poking ominously out of the surf.
Luckily, she eventually realised something was amiss and returned a few short yards to the beach.
It was only then she realised how close she had come to being devoured.
Simone added: “The people at the beach told me that just 16 feet behind me a shark was swimming.
“I was so terrified I didn’t go back into the sea again for days!”
Thank God for her life, she is so lucky.