Brianna Gunderson, right, says swimming can help build trust between parents and children -- one of the reasons she brought daughter Ava, 2, last week to an open infant swim at the Family Swim School in Lakeville. Gunderson brought her 7-month-old son, Liam, to the session, too, for his first experience under water. Swimming, Gunderson says, is "an essential lifetime skill that will help them with their motor skills and everyday use, living in the Land of 10,000 Lakes."