When Michael Phelps was 7, he was scared to put his head under water. Then he became the greatest swimmer ever.

Boomer Phelps is not even 7 months old (he was born in July), and he's already submerging. With the help of the woman who taught Phelps to swim. In the city where Phelps grew up. Good luck, 2036 Olympic field!

Michael Phelps shared video of Boomer, aka Boom-Boom, on Facebook Live on Monday from Meadowbrook Aquatic and Fitness Center in Baltimore, where he and his wife, Nicole, were giving their baby his second in-pool lesson.

Boomer can't swim ... yet. When he went underwater Monday, he threw a bit of a fit.

He'll get there, though. He was getting lessons from Cathy Bennett, Michael Phelps' first swim instructor and the director of the Michael Phelps Swim School.

“Today was very good, very successful,” Phelps said. “The process has started where he gets to become more water-safe and relaxed, comfortable in the water.”

— Jonas Shaffer