Elizabeth Christensen loves the water. She swims up to three times a day, loves doing laps and diving in the deep end – and she’s only 16 months old.

Adam Christensen, Elizabeth’s father, posted a video of the Texas toddler swimming alone in a pool in August last year, but it recently went viral. Without any flotation devices, the toddler paddles using her arms and legs across the length of the pool. Along the way she rolls from her stomach to her back for air. Her parents are heard in the background shouting words of encouragement.

“Go go go go! You can do it,” Elizabeth’s mother yells. “I can’t believe she made it across the pool.”  

The video has sparked controversy. No one is in the pool with the toddler and lifeguards aren’t seen on camera. But Adam, spoke to the media to explain and defend the clip.

“We didn’t teach her ourselves; we wanted a professional, somebody that was certified to do that. But we are still able to recognize warning signs. As you can see in the video, she’s not coughing or choking. She’s gasping, but that’s normal,” he told CNN.

In the description for the YouTube video, Christensen notes that he is a registered nurse and his wife is a former lifeguard. Their daughter was trained with an ISR (infant swimming resource) instructor that teaches children under four how to survive if they accidentally fall into a body of water.

“Sometimes the difference between life and death can be six inches of water and their ability to flip over on their back and take a breath,” Christensen writes in the YouTube description that urges other parents to teach their babies how to swim. In a 2012 report, the U.S. Center for Disease Control said unintentional drowning was the leading cause of death in children between the ages of 1 and 4, HealthDay reports.

Despite Christensen’s confidence in his daughter’s swimming abilities, he had his doubts.

"When I first watched her in there, every time she went face down I was like, 'Oh, my goodness, she can't breathe.' I was just worried to death, but the instructor assured us that she was just fine," he said.