What is up with the guards?

This is my fifth day in Goa, and every time I was in the water, I noticed that whenever a foreigner entered, the guards asked all Indians to come out, citing that the water was too high—even though many people didn’t go beyond knee-deep. I had an argument with the guard about this, and they threatened to call the police. Before entering the water, I even asked the guard if it was safe, and they said nothing. Plus, I didn’t go too far—only up to my waist.