A former cub scout leader, swimming coach and first aid instructor has been found guilty of 79 counts of sexually abusing more than a dozen boys over about 30 years.
The jury returned unanimous verdicts on all 79 counts at Lewes Crown Court at the end of a trial that started a month ago.
Judge Christine Laing, the honorary recorder of Brighon and Hove, told Silvester that he would be sentence in February. He was remanded in custody.
Silvester, 60, used his position to take advantage of children – some as young as seven or eight years old – even babysitting some of them after winning the trust of their parents.
Silvester, of Locks Hill, Portslade, abused boys while he volunteering as a cub leader, in Hove, and as a swimming coach at the Aquarena, in Worthing.
The former nurse taught first aid with St John Ambulance and started his own first aid training business, using it to abuse more boys, some of them described as vulnerable.
Lesley Bates, prosecuting, told the jury at Lewes Crown Court: “Over this period of about 30 years, Ian Silvester befriended boys and their families so that he was taken in and trusted.
“To some, he became a part of the family. Parents trusted him to babysit their children. He held different roles which gave him an air of respectability but also unlimited access to young and very often vulnerable boys.
“He was a cub scout leader, a diving instructor, a St John Ambulance trainer and a first aid trainer.
“In each of those roles, he was able to persuade these young boys to do what he asked without question.
“He took advantage of their young age and immaturity and his position of trust to play games or create activities which made what he was doing appear both innocent and legitimate.
“As a cub scout leader it was called ‘jungle treatment’. As a diving coach it was training to prevent the student being distracted when diving.
“As a first aid training provider, it was to train boys to act as a casualty and play dead. As a babysitter it was learning maths or playing a game.
“Whatever the description of it, it all involved the same sort of touching and, the prosecution says, the same motive: his sexual gratification.
“This touching happened to 19 different boys. Some were alone. Some were together. Some were told to do it to each other – no doubt to reinforce the legitimacy of it while also getting gratification from watching them.
“Ian Silvester was arrested and interviewed on a number of occasions. For the most part, he accepted that he had done the touching alleged.
“But he denied that he was motivated by sexual gratification and denied that he had a sexual interest in boys.
“However, when the police arrested him (in 2021), they searched his house and seized a very large number of electronic and digital devices.
“And on those devices, they found a huge amount of material which, the prosecution says, proves the lie that he was not motivated by sexual gratification and had no sexual interest in boys.
“The material falls into a number of categories and some footage and images from each category will be shown in evidence.”
In his role as a St John Ambulance instructor and first aid trainer, Silvester used young boys as casualties in first aid demonstrations.
Miss Bates said: “At least part of this training had nothing to do with first aid but everything to do with his sexual interest in touching young boys.
“Under the guise of them pretending to be a casualty, the boys would have to lay on the floor and play dead while Ian Silvester touched them.
“It was always the same thing – on the floor, top off, touching their bare chest, torso and sides while he was lying between their legs.
“It bore no resemblance to what happened when there was an actual first aid event or course.
“Sometimes they would have a ‘practice’ before going to an event or course and then again afterwards but this touching never happened during the event or course.”
The jury were shown clips of a number of videos of the boys made by Silvester who denied all the charges.
He is due to be sentenced on Friday 7 February.