These are sting-rays at an amusement park. We were surrounded by three of these things at the beach next to the condo we stayed at. The sting-rays were three times this size and Josh almost stepped on one. A storm was coming in, so it was hard to see, lot's of sand. The sand comes right on top of the sting-rays and you can barely see them. Luckily, I was looking under the water at the time Josh was walking backwards and there was a huge one right behind him. I started screaming. He couldnt hear me under the water. I got up and was yelling and he didn't believe me, He thought I was kidding. Our other friend Josh saw it too. It was fun and scary at the same time.