Tide Surfing(冲浪chōnglàng) is a special swimming(swimming is the activity of swimming, especially as a sport or for pleasure) sport. Here it means that swimmers perform their swimming skills against the tides in the time of Qiantangjiang Immense Tide in the eighth Lunar month every year.

Qiantangjiang Immense Tide is a natural marvelous spectacle. The rough sea-water pours into the mouth of Qiantangjiang River from the fifteenth to the eighteenth of the eighth Lunar month every year, and immense tides form because of the great quantity of water pouring into the narrow mouth of the river. The tides are extremely magnificent, but the sons of the fishermen bom and brought up there were not threatened off when faced up the sky-scraping waves. On the contrary, Bey swam against the tides with their skills developed from childhood, emerging find disappearing among the waves, which is acclaimed as the acme of the perfection, so they win themselves a nickname "Tide Surfers".

Qiangtangjiang Tide Surfing has a long history. The word "tide surfer" appeared early in the poem by Li Yi in the Tang dynasty, "I got married to a merchant in Qutang, and every day he leaves me alone. If known the tides come regularly, I'd have married to a tide surfer." Tide surfing came to its summit in the Song dynasty. A great number of diaries, poems and articles described It vividly then, of which "Old Stories of Martial Arts Circles" by Zhou Mi is a representative. It says. "Tide in Zhejiang is magnificent in the world. It tops from Jiwang to the 18th of the eighth moon... When they come nearer, they become snow mountains from a line from the sky with great thunders. They shake the world, gulf the sky and cover the sun... Hundreds of young men who were good at swimming in Wu wore their hair down with tattoos on body, held ten big colored flags in hands, competing against the tides, appearing and disappearing among the significant waves. They jumped high out of the water without making flags wet to show their skills."

It was banned by the government in the Southern Song dynasty because it was thought dangerous. It was deeply loved by the common people and in the Qing dynasty, there were still people there performing tide surfing, but the scale was not so big as in the Song dynasty.