Be calm, fan boys and girls, for Gerard Butler is not actually on the brink of death. He just nearly drowned while filming some surfing movie; he was rescued and taken by an ambulance to the Stanford Medical Center for an exam. How and why did he nearly asphyxiate underwater? Because Hollywood people are stupid and he was filming his (probably horrible) surfer movie at Mavericks, a place known for killing people with its stories-high waves.
(The accident took place at) at Mavericks, a famed Northern California surf break known for treacherous, stories-high waves.
Butler had not surfed much before the movie but had made an effort to improve his surfing and water skills for the film.
Maverick's cold water and giant waves have made it a Mt. Everest-like conquest for some surfers.
In 1994, Mark Foo, a seasoned big-wave surfer from Hawaii, died while surfing Mavericks.
Ten-time surfing world champion Kelly Slater has also talked about how dangerous the wave is after getting held down after a wipeout there in 2000.
So taking an inexperienced actor on the waves that killed professionals is probably a smart idea. Good job, Hollywood. At least you're doing your job to cull the herd. We only have so many resources after all.