According to the Institute of Fisheries Research in Kinmen Islands, the luminous sea phenomenon has been monitored for a long time. The people of Kinmen Island in Taiwan call the mysterious glowing beach in the spring a "custom" (blue tears).

"Spades" are formed when ocean waves rush into algae, causing them to glow green. This phenomenon is evident from mid-April to May when sea water warms, according to Li Chia-fa, a scientist working at the Fisheries Research Institute.

Hsu Chin-hsi, Head of the Kimmen Photographer as‌sociation, thinks the archipelago’s terrain is convenient for visitors to explore. The most beautiful spots for visitors to observe the "rules" are Lake Cihu, Shangyi Beach, Houhu Park, Guang’ao Sea Embankment in Jinsha Town, Liaolo South Stone Weir Park in Jinju Town.