The Greater Meaning of Water(2010)

Freediver Max Avery (Justin Flint Williford) journeys to his inner-most depths as he pursues competitive freediving as a relief from a chronic lung disease. Yet his passion for the extreme sport is widening a rift between him and his father (Mark Brunetti), a physician, who hears his son's risky descents will cost him his life. As Max trains for one last world record attempt, he must convince his father that the perilous dive may be his only chance of triumphing over his illness.

Official site