ISB has a swimming programme that consists of a Senior Team (Grade 7-12) and a Junior Team (Grade 3 - 6). Both of these teams practise at the VUB pool. The Senior Team practises four days a week in the mornings. Swimmers are dropped off by parents and brought to school by bus. The Junior Team practises two mornings and one afternoon per week. Both teams compete at swim meets in and around Belgium during the season. The Senior Team competes in the ISST Championships at the end of the season and the Junior Team competes in a local schools championship meet.