The primary reason for adopting yellow fluorescent discs is to be fan-friendly in being able to attendees and stream viewers to track the disc. All broadcasted games will be played with a neon yellow disc. Non-streamed games will have the choice of playing with the white or neon yellow disc.
The idea of a flying disc specific for beach ultimate is not new. WCBU cites "heat absorbing research" to support their choice of bright yellow over black, bright orange, dark red, red, royal blue, light blue, or sparkle blue UltraStar ultimate sportdiscs. Specifically:
Heat absorbing tests show that the fluorescent yellow disc stays firmer than other colors when exposed to the sun, while in-competition tests showed that there is not a significant impact on play using a fluorescent disc.The tournament host recommends teams to "play and practice with yellow disc before the WCBU starts."