Four American children and their parents had to be rescued by lifeboat crews after getting cut off by the tide.
The family, on holiday from the United States, became stranded on the bank of the River Gannel in Newquay, Cornwall on Friday evening.
The crew of Newquay's RNLI lifeboat carried the young girls to safety.
An RNLI spokesman said the family were unhurt, but had been shocked at how rapidly the river levels had risen.
"The group was aware of the tide times but hadn't appreciated how soon they would be at risk of being cut-off," he said.