Philip Longbottom, 67, from Shipley, West Yorkshire, will serve a minimum of seven years in jail after pleading guilty to more than 40 serious sexual offences at Bradford Crown Court.
The father of three and former scout leader invited victims to his home or took them on foreign holidays, camping and swimming trips, often giving them and their parents money or expensive gifts.
Longbottom, who was also involved with a CB radio club, the church boys' brigade and the sea cadets, abused 12 boys and teenagers between the ages of seven and 19 between 1968 and 1996, with a further offence in 2010.
The youngest victim was seven and the oldest 19.
He was given concurrent life sentences, with a minimum term of seven years, for 16 offences of rape and buggery against six victims.
He also received four years for 21 counts of indecent assault, four years for a count of assault with intent to commit buggery and 16 months for four counts of indecency with a child. The sentences will run alongside the life sentence.
Judge Jonathan Rose told his victims in court: "No sentence I can impose can ever adequately compensate you for what you endured in your childhoods."
