They competed in the 'butterfly'.
swimmers doing the 'butterfly'
a 'social butterfly'
(..) - This house stinks. - It's the worst place - ... I've been in my entire life. - Oh, yeah. Hey, it's nothing our butterfly curtains couldn't fix. I read somewhere that an empty room is an opportunity. - Where did you read that? - It doesn't matter. I read it and it's great. We'll put the bed there. (..)2015 Inside Out