By Greg Farrar Cameron Simmons takes a big gulp of air before bobbing underwater as K.C. Gere (left) and Katie Hirshberg (in background) teach two children’s classes, part of a coordinated worldwide swim class record attempt at the Julius Boehm Pool.

By Greg Farrar Cameron Simmons takes a big gulp of air before bobbing underwater as K.C. Gere (left) and Katie Hirshberg (in background) teach two children’s classes, part of a coordinated worldwide swim class record attempt at the Julius Boehm Pool.