A dad watched in horror as the inflatable swan carrying his two young daughters was swept out to sea.
The father had been holding a line tethered to the blow up bird in the shallow waters off Minehead in Somerset on Saturday afternoon.
But the rope slipped out of his hands and the float, along with his 7 and 9-year-old daughters, drifted out to sea.
He shouted at the girls to stay on board while calling 999, Somerset Live reported.
The RNLI sent out two boats at 3.30pm
"He waded into the water and tried to swim out to them but the thing was just moving too quickly and he couldn't get near it,"volunteer lifeboat helm, Phil Sanderson, said of the dad.
"He did exactly the right thing: he shouted to the girls to stay on the inflatable and then the family dialled 999."
The lifeboats were on scene within a few minutes and were joined by a coastguard helicopter which had been on exercise in the area.
Mr Sanderson said by the time the lifeboats arrived the inflatable was almost half a mile offshore - and still moving rapidly seawards.
"Clearly the girls were very frightened by then but we soon had them aboard and reunited with their family," he added.
The town's lifeboat association are now trying to work out why no red flags were being flown on the sea front advising people not to go into the water with inflatables.
Minehead RNLI chairman Bryan Stoner said: "The system was put in place some years ago after a lot of pressure from us because we were dealing with a real spate of incidents like this, one of which involved a fatality.
"On this occasion, however, it appears the system has failed, though through good fortune no-one has come to any harm."
