Tens of thousands of people lined up along San Diego Bay to watch the annual Red Bull Air Races this weekend.
Organizers call the two day competition the fastest motor sport on earth. The small aircraft can get up to 230 miles per hour while making hairpin turns around pilons floating in the water.
The pylons are actually made of a paper thin material. So, even when the planes hit them, there is rarely any damage to the aircraft.
Organizers expected about 100 thousand people to show up to watch this weekend. They won't know until the end of the weekend, if they met that goal.
The sport started in 2001, and has been gaining popularity ever since. The 15 pilots who compete are from all over the world. This year's youngest pilot is a 25-year-old American.
