American duo Makuakai Rothman and Kalani David from team RVCA won this year's Qiantang Surfing Shootout challenge. Photos provided to China Daily

It's raining and the wind is blowing, but out in the middle of the water four international big wave surfers await the oncoming surge. The wave arrives and the surfers mount their boards, riding it as long and as far as they can. However, this is no ordinary wave. They're riding the silver dragon, the Qiantang tidal bore.

Every year around the time of the mid-autumn full moon, hundreds if not thousands of people line up on either side of the Qiantang River in Zhejiang province to watch the annual tidal wave known as the tidal bore. A tidal bore is when an ocean wave travels up a narrow path against the regular current of the water. This usually happens in rivers.

Commonly known as the Silver Dragon, the Qiantang River tidal bore happens to be China's and the world's longest inland surge.

Since 2009, in a move to help promote surfing and extreme sports, international surfers have been allowed to ride the inland surging waves. This year four teams from the US and Australia competed in the Red Bull sponsored Qiantang Surfing Shootout challenge.

American duo Makuakai Rothman and Kalani David from team RVCA won this year's Qiantang Surfing Shootout challenge. Photos provided to China Daily

A surfer rides the waves at Qiantang River in Zhejiang province last week during the annual tidal bore.

RVCA, Ocean and Earth, The Crew, and Vision streetwear in teams of two competed in the shootout challenge during the three-day Mid-Autumn Festival. The American duo Makuakai Rothman and Kalani David from team RVCA came out on top and won $10,000, edging out one of last year's winners; Australian Phillip MacDonald of team Ocean and Earth.