Two young sisters have suffered profoundly since the father of one of them tried to drown them in a flooded quarry, a court was told.
The three leapt from the quarry's sheer face last December
One of the girls, nine, has had post traumatic stress disorder since her ordeal, Mold Crown Court heard.
The other girl, six, who had screamed for help while in the freezing water, had also changed.
The man, who is 36 and from Gwynedd, was jailed for eight years after earlier admitting attempted murder.
An impact statement told how both children had changed since their traumatic experience, Wyn Lloyd Jones, prosecuting, told the court.
The eldest had nightmares, panic attacks during swimming lessons and refused to leave the house at times and blamed her mother for what had happened.
She would not shower or bath and made excuses not to go to school.
The girl would pace round the house saying things like, "I am drowning," and was found to have had severe post traumatic stress disorder.
The younger girl had also changed while their mother has suffered a nervous breakdown, was on long-term sick and needed medication to help get her through the day.
The man, who cannot be named, had taken the girls to the Bryn quarry near Bethesda last December after splitting up with their mother, the court heard.
Before leaping into the freezing water from a sheer cliff face he phoned the girls' mother and said '"Say ta-ra to the kids".
Mr Lloyd Jones said: "It seems that what he actually did was hold one child on each hand, one on either side, and them jumped in.
The man (right) was sentenced to eight years in prison
All three were submerged and Mr Lloyd Jones said the two children were not capable of swimming in such conditions. They had only had lessons in a toddler pool and the eldest girl was known to be petrified of water.
Within moments the man began to help the girls out of the water and all three were rescued by an RAF winchman and taken to hospital suffering with hypothermia.
Home Office pathologist Dr Brian Rogers said the girls were in danger of dying within three minutes in the conditions.
Mr Lloyd Jones said it was clear that the man knew the girls would be unable to save themselves.
"The eldest girl later described how her younger sister was asking for help and she tried to do so," he said.
Jailing him on Friday, Judge Mr Justice Roderick Evans said people must learn they were in danger of long terms in jail if they used their children "to get at their former loved ones".
After the case had ended, the girls' mother issued a statement saying it would now be her focus "to guide and support the girls to enable them to recover fully from the trauma they have suffered".