The challenge attracts hundreds of international competitors who jump off a ferry into the rough ocean near the infamous Alcatraz Prison and swim to San Francisco Bay.
Mr McMahon, 63, landed in the US just two days before the gruelling event, which has a 26-year history.
"There were about 550 competitors," Mr McMahon said.
"I came first in the over 60s age group, fifth in the wetsuit category and ninth overall."
"I can say an eight-year-old boy beat me."
The 2.5km swim, in 25 knot winds, took Mr McMahon 51 minutes to complete but he said there were still people swimming to shore 45 minutes later.
Owner of the Ipswich Swim Factory in Woodend, Mr McMahon had trained in his acclimatised pool at home of 15 degrees, which happened to be the exact temperature of the water on the day. The only heart-stopping moment in the event was when Mr McMahon noticed a dark shadow moving over his submerged head.
"It turned out to be a flock of pelicans flying overhead," he said.
Although a fun and challenging event, the seriousness of what they were doing was compounded when a female competitor suffered a heart attack and died during the challenge.
"A few others suffered hypothermia," Mr McMahon said.
After completing what he called "my Everest", Mr McMahon said once was enough.
"It's a long way to go for a few days and I've achieved it now already." |
