Coastguards put out a warning to shipping after a waterspout was seen sweeping along the South Coast just after dawn on Sunday.
Pete Machin photographed the waterspout over Brighton's Pier
Ambulance crews also had calls alerting them to the whirlwind over the sea as it moved from West to East Sussex.
It is thought to have dispersed by the time it reached Telscombe Cliffs.
Eyewitness Peter Machin, who lives on Brighton seafront, said he watched it for 10 to 15 minutes. "I was absolutely gobsmacked," he said.
"I was woken up early because there was a party going on upstairs and I looked out and saw a black cloud with the funnel underneath.
"It was moving towards Peacehaven and seemed to be getting bigger and bigger as it got closer.
"I am on the seventh floor and I've got a very good view of the sea.
"The wind wasn't that extreme - but it was quite blustery and the sea was choppy further out."
Solent Coastguard said its warning was issued as a precaution but there were no reports of ships in trouble.
A spokesman said the waterspout stayed over the sea and dissipated as it moved towards land.