Tracy Aston, 35 and Lisa Coggins, 33, drowned after entering stormy seas after a night out on a girls' holiday at the Costa Brava resort last October.
The pair, from Birmingham, had entered the sea after the group of friends decided to take a walk along the beach at around 2.30am.
An inquest held at Birmingham Coroner's Court on Monday heard how the pair had been knocked over by a wave and swept out to sea.
Italia Sassano, who was also on the holiday, told the court that Aston and Coggins ran a few steps into the sea when "they both fell down and couldn't seem to regain their footing," according to a report in the Birmingham Mail.
"A few waves came along. I could now see there was something very wrong as none of them were getting up," she said in a statement to the court.
"Suddenly out of nowhere a rather large wave came and pushed Joanne forward towards the shore where I was able to grab her.
"As the wave went out it took Tracey backwards and under when I then lost sight of her."
The coroner, Lousie Hunt recorded “accidental death” describing it as an "awful tragedy".
But speaking outside the courtroom after the inquest, Aston's mother Tina Tysall, said: "There were no warning flags on the beach that night.
"Had that been the case Lisa and Tracey would never have entered the water. This is a very dangerous stretch of beach.
"Two young lives would not have been lost had there been basic safety procedures in place."