I saw my teacher on the beach

Date: 8/31/2019

My friends and I were on a beach. It was low tide and there was a couch in the middle of the water so we sat on it. There were a lot of people playing in the low waves when I saw my former teacher playing with two other people and a kid with ponytails. They were rolling and throwing the inflatable rings to each other. I told my friend that I saw our teacher and pointed her out. He immediately grabbed a rock and threw it hard which then landed right in front of my teacher and made her startled. When she was searching for where it came from, I waved my hand and pointed at my friend. Seconds later, she and her group were now in front of us and started playing again. Our former teacher didn't say anything to us so we decided to join with them.