Lucky you, 4 years in paradise!
That is a funny story, did they show up in their scuba suits?
In Canada it's completely legal to go shirtless outside anywhere you like, whether you are male or female, we don't have any laws stating any person is required to wear a shirt!
We are also aloud to swim in our birthday suits in any lake we like. For the most part nude beaches seem to be segregated from typical public beaches but there is actually no law regarding that.
What a difference from the Middle East, I was in Doha Qatar last year and despite of how hot it was women were required to wear swim attire that covered our shoulders and our knees. Men and women didn't even swim at the same beach area, it was all segregated, men, women and families (which included women and children of either gender). There were signs up with a bikini on them inside a red circle with a line through it. No Bikinis aloud. I hope some naive Canadians don't show up and think its meant to be a nude beach!