A visitor from China nearly drowned Friday, when he was walking on the reef at Hanauma Bay at 12:30 p.m. The man, in his 40s, could not swim, according to his family.  He fell into about 4-to-5 feet of water.  Lifeguards pulled him from the water and brought him to shore, performing CPR.  He was then transported to a hospital in serious, but stable condition.