That excuse doesn't work since this is a girls' swim class, not a women's swim class. If they are trying to play the muslim card then they need to have a muslim only class. He should demand that as her father, his religion demands she be chaperoned by an adult male relative at all times... uh, oops, hmm, isn't that what muslim women have to abide with, too?
seperate accomadations for the sex’s in swimming goes way back before anyone heard of muslims...I took swimming during the 50’s and night swimming was all female on certain days and male on other days....The girls didn’t have to be bothered by boys being boys and teasing the girls...it was a good idea then and a good idea now....