A 72-year-old former teacher at a top boys school who "hypnotised" his victims before carrying out sexual assaults has begun a 27-month prison sentence.
Peter Clulow resigned from Haberdashers' Aske's Boys School in Elstree in the 1980s after two teenage boys accused him of molesting them.
Clulow was banned from working at any boys schools, but nothing was done to prevent him taking in private pupils.
And it was during private maths lessons that Clulow had access to young boys who he preyed on during sailing trips aboard his boat The Saraband.
Peter Shaw, for the prosecution at St Albans Crown Court on Tuesday, said: “The defendant had been a music teacher at Haberdashers' Aske's for 23 years, but left in 1985 following an allegation by two fourth form boys that he had indecently touched them while on his boat during the summer holidays.
“Notes from the school show he initially denied the abuse but the two boys amazingly had taken an audio recording device on board that captures some of the comments made by the defendant.
“When played to him he offered his resignation from his position at the school, which was accepted by the headmaster there and then.”
Mr Shaw added: “He was not prosecuted for those matters as no formal complaint was made to the police but he admitted to the abuse to the police later.
“The department of education carried out an investigation after he left, which said he should be prohibited from working at all boys schools, but it did not stop providing tuition in the home. That left an opportunity for him to carry on,” said Mr Shaw.
Clulow went on to abuse three more boys who had gone to the “respected and well-liked” teacher for help with maths.
It was not thought unusual for pupils to take trips on Clulow's boat docked in Portsmouth as sailing was taught at Haberdashers' Aske's.
During these trips Clulow told the two friends he could hypnotise them.
As one of the boys, aged 16 at the time, pretended to be hypnotised, Clulow assaulted him. This happened on at least one more occasion, the victim told police years later.
The second victim, aged 16 , was sexually assaulted after being hypnotised by Clulow, after agreeing to go on his boat between 2000 and 2001.
Clulow would indecently assault the boys while taking their hands and making them do the same to him.
The youngest victim, aged 15, was again hypnotised and told to fondle himself after Clulow said he had changed his sex to that of a woman.
When police recovered the secret video of the abuse at his home he was heard encouraging the boy to play with his “breasts” and asking if it felt “good”.
After Clulow's arrest in September 2006 police found numerous pornographic images of adolescent boys on his computer.
Clulow, now of The Lawns, Hemel Hempstead, had pleaded guilty at a previous hearing to five counts of indecent assault on a male, inciting a child into sexual activity and 16 counts of possession of indecent images of children, including what the judge called one “particularly disturbing image of a young child”.
Kaja Reiff-Musgrove, for the defence, said Clulow had thought by hypnotising his victims they would not suffer by what he subjected them to, but now accepted the damage his actions caused.
She said he had faced up to what he had done and had told his church, which supported him.
He was now seeking help, which was not available when he resigned from Haberdashers' in 1985, to overcome a “growing problem”.
Miss Reiff-Musgrove said: “This has been a real fall from grace. This is a very public fall from grace, which is significant punishment.
“From the numerous references he was clearly a person held in great esteem by a large number of people.
“He is an intelligent man that had a number of gifts and wanted to assist people and while on remand in prison has helped a number of people with literacy.
“The pre-sentence report says he used his position as a teacher and his boat to abuse children, but that was not the case, it is ancillary.”
Judge Stephen Warner said: “In committing these offences against these young boys you were abusing your position of trust as a teacher.
“You were trusted by the boys and their parents and abused that trust over a number of years for your own gratification.
“This is a tragedy for everyone concerned. Not only for the victims, but for you. You clearly have great abilities as a teacher.”
He added: “Your propensity to abuse young boys in your charge was known in the school where you worked and by the department of education.
“You were allowed to leave in 1985 with the prohibition of teaching in any boys school, which was completely inadequate as you went on to teach boys privately.”
Clulow will serve half his sentence before release, with 214 days on remand to count towards sentence.
He was banned from working with children and must sign the sex offenders register.
A sexual offences prevention order was imposed giving police access to Clulow's computer and banning him taking pictures of any person under the age of 18.