For those of you not familiar with the sport of surfing, today is an absolutely huge day. It's the Mavericks Surf Contest at Half Moon Bay here in California.
This is one the sport's premier big wave contests, and without question the toughest. The water at Mavericks never gets above 55-degrees and waves at the spot can consistently be more than 50-feet high. The men and women that surf are truly amongst the top surfers in the world.
An underwater rock formation is partly responsible for the spectacular breaks that can result in towering walls of water, which can deliver harsh punishment to the surfers if they wipe out. Mark Foo, a legendary big-wave surfer from Hawaii, died while trying to surf Mavericks in 1994.
The contest isn't held at the same every year. Contest organizers use the help of science to determine when the biggest waves are coming in and then give the contest the green light. This year the decision to have the contest was made on Thursday, giving surfers around the world less than two days to find their way to Mavericks.
If you're wondering why people surf a spot like this, particularly when it's so dangerous, you're not alone.
But a number of people consider Mavericks to be the Mount Everest of surfing. Which means one of the reasons for surfing it is simply to see if you can do it.
You can read more about what it's like trying to catch a 50-foot wave (it's - surprise - not easy) thanks to this New York Times article, which also gives some background on the event.
If you're interested in watching the event, there's a live web cam capturing some of the action.