THE teaching aspirations of Warrnambool's former head lifesaver are over after he was placed on the sex offender register for having sex with a 15-year-old.Brad David Williams, 22, of Pye Court, pleaded guilty in the Warrnambool County Court on Friday to one charge of sexual penetration of a child aged under 16 years.In sentencing, Judge Jane Campton said that in her opinion, Williams being placed on a sex offender register was a severe and unnecessary punishment and there should be exceptions.Williams has completed two years of physical education studies at university and now plans to change his course.The court heard that between December 2006 and April last year, Williams and the schoolgirl had a sexual relationship.After completing year 12, Williams was offered a physical education and sport traineeship in 2006.The program was to show Williams what it was like to be a teacher.During 2006 a year nine student obtained Williams' mobile telephone number and started sending him text messages. The two started messaging each other, leading to dating and then an overnight stay at a Warrnambool caravan park on November 30, 2006.The relationship continued until October last year when the victim spoke to school staff.Defence counsel Michael Turner said Williams admitted the girl was 15 years old when they formed a relationship.He said the ramifications for his client were life-changing as Williams would be placed on a sex offender register and not be able to be a teacher. Mr Turner said Williams genuinely cared for the girl and while the question of her age had been raised, both he and the girl agreed to the relationship continuing.He said Williams was an outstanding young man on every level and had been a primary and a secondary school captain.Williams was the head professional lifeguard at Warrnambool last summer and had represented the state in swimming and surf lifesaving as well as playing football for the Geelong Falcons.A psychological report found that Williams was most unlikely to reoffend. In a victim impact statement, the victim said she felt used and sad.Judge Campton said Williams had tendered glowing references but that he had become a recluse and isolated. She said he admitted he should have waited until the girl was 16 but felt strongly for the girl and thought she felt the same way.Judge Campton said Williams had paid a severe penalty in losing his chance to become a teacher.He was sentenced to do an 18-month CBO, complete 160 hours' community work and undertake programs as directed. He will be registered as a sex offender for 15 years.