For a local, family friendly, swimming hole look for the small beach area on Cedar Road just before Cedar Bridge and the turnoff to Cedar’s Main Street area. The beach is a little larger than most areas on the river and is wide open so you can keep a good watch on your young ones. There are so many swimming holes along Nanaimo River. Under the Cassidy bridge is a great place to swim or start a tube down the river.
For more info on river locations, check out the following link: http://www.ourbc.com/discover_bc/rivers/swimmingholes/nanaimo_river/nanaimo_river.htm