A county parks worker saved the life of a man who nearly drowned at McNears Beach on Wednesday evening.

Louis S. Hernandez, a county parks seasonal assistant, was flagged down about 6:30 p.m. by a fisherman who said a man was flailing in the water near the park's fishing pier.

Hernandez promptly called 911, then grabbed a life ring and rushed out to help, tossing the preserver to the struggling man and pulling him along the pier to shore.

"It was a near drowning," San Rafael Battalion Chief Jeff Buscher said. "The maintenance worker was alert."

Chief park ranger Rob Ruiz, who arrived minutes after the dispatch, joined fire officials in praising Hernandez. "Louis has worked for the department for several years and did a great job," he said.

When San Rafael Capt. Ryan Goodwin and his fire crew arrived minutes after the 911 call, Hernandez was at the side of a 29-year-old East Bay man who was convulsing at the shoreline, suffering from hypothermia. He was taken to Marin General Hospital for treatment.

Ryan said the victim dropped his car keys into the bay while on the pier — and dove in to try to find them. After a fruitless search, he grew tired and began to struggle in the cold bay water. Another man watching from the pier alerted Hernandez.

Goodwin said the parks worker stayed with the fire crew to help as the victim's wet clothing was removed and he was warmed with blankets. "Louis was there the entire time helping us," Goodwin said, adding he has recommended the department issue a commendation to recognize the park worker's efforts.

Buscher said the incident provides a number of lessons.

"The county park worker took immediate action," he said. "The biggest first aid you've got is 911."

As a result of Hernandez's action, "someone is alive," Buscher observed.

Contact Nels Johnson via email at njohnson@marinij.com. Follow him at twitter.com/nelsjohnsonnews