They competed in the 'butterfly'.
swimmers doing the 'butterfly'
a 'social butterfly'
(..) - You should. - Sit down. Friends, you saw enter here a waif, a gamin, a lowly caterpillar. We open the cocoon but it is not a butterfly that emerges. - It's not? - No, it is a bird of paradise. Lights! Curtain! Oh... (..)1957 Funny Face