Blue Switch Day
On 2nd May 2000, the US government discontinued the practice of Selective Availability, which had intentionally degraded the accuracy of GPS signals for civilian use. This decision, often referred to as "flipping the blue switch," instantly improved GPS accuracy tenfold, from approximately 100 meters to within 10 meters
The very next day, 3 May 2000, Dave Ulmer, a GPS enthusiast, tested this newfound precision by hiding a black bucket containing a logbook and trinkets in the woods near Beavercreek, Oregon. He posted the coordinates online, inviting others to find it. This event marked the inception of geocaching, a global treasure-hunting game that now boasts millions of participants worldwide .
To commemorate this pivotal moment, geocachers celebrate "Blue Switch Day" annually on 2nd May, honouring the day GPS technology became widely accessible and the adventure of geocaching began.