Tobias was born June 1 and is named after his great grandfather.

Hamilton was four months pregnant when the couple announced that they were expecting. She continued swimming and surfing through the first six months of her pregnancy, Huffington Post reported.

She competed in the World Surf League's Women's Pipe Invitational when she was 3 1/2 months along.

Hamilton, according to her website, lost her arm when she was attacked by a 14-foot tiger shark in 2003 when she was 13 years old. A month after the attack, she returned to the water. The next year she won her first national title. Her first competition was in 1998 at the age of 8.