Kenneth Starks, of Strachur in Argyll and Bute, was also put on the sex offenders register for 18 months.
A prevention order was placed on him, restricting him from approaching or being alone with children under 16.
Starks was previously found guilty of three charges of sexual assault at the DG One leisure centre in 2014.
He was convicted of swimming towards children in the pool and touching them.
The retired teacher was also found guilty of a breach of the peace.
A 64-year-old man found guilty of sexually assaulting youngsters in a Dumfries swimming pool has been ordered to carry out 200 hours unpaid work.