In ancient Chinese legend, there were eight immortals (Iron-Crutch Li, Han Chung-li, Chang Kuo-lao, Lan Tsai-ho, Ho-Hsien-Ku, Lu-Tung Pin, Han Hsiangtzu and Tsao Kuo Chiu). Each was a master of individual and unique abilities. They were once gathered and drinking in Penglai Pavilion and on the verge of drunkenness, Iron-Crutch Li suggested taking a trip to the sea. The other immortals agreed and upped the ante, saying they could not take a boat but had to cross the sea using their martial skills.
Han Chung-li went first, throwing his palm-leaf fan onto the sea, laying on top of it and floating away. Next, Ho-Hsien-Ku threw her lotus onto the water and stood on it, also floating away. Then, Lu-Tung Pin, Chang Kuo-lao, Tsao Kuo Chiu, Iron-Crutch Li, Han Hsiangtzu, and Lan Tsai-ho each threw their various personal treasures onto the water and one after another, using supernatural powers, crossed the depths of the sea.
The original meaning of “八仙过海 各显神通” is eight immortals crossing the sea with their personal and unique abilities. Now it means each person trying their best, for all one's worth. （from: 互联网）