“Dragon Boat Competition” started as early as during the Warring State, where many canoes carved in the shape of dragons were competing with the company of drum beats, which was a semi-religious and semi-entertaining program of ritual provided as entertainment to deity and people. In the Great China Area, Japan and Ryukyu, dragon boat paddling on Dragon Boat Festival is intended to expel plaques and exorcism. Ancient people treated the boats are tool to send away disasters and evilness and considered it best to send away evilness as soon as possible, which then led to the custom of dragon boat competition.

 
Mainland China

The southern area of mainland China preserves the custom of Dragon Boat Festival better and shows stronger festivity than the Northern China, where many local areas hold different scale of dragon boat competitions.
 
Hong Kong

When Hong Kong first opened up for trade, the Chinese would carry out some festival activities in celebration of Dragon Boat Festival by holding dragon boat competition, using dragon boats to carry out the rituals, traveling via dragon boats, and eating rich dumpling. Prior to each dragon boat competition, a “paper lantern release” ritual will be held.
 

Taiwan

Taiwan’s Dragon Boat Festival preserves a number of customers for Chinese Dragon Boat Festival, including easing rice dumpling, drinking Xiong Huang wine, expelling five evilness, drinking water at noon time, taking a shower at noontime, egg-standing, and dragon boat competition. Taiwan started holding dragon boat competition in 1736. At the time, Taiwan Governor Jiang, Yuan-Jun hosted the friendship competition at the Ban-Yue Pond of Fahua Temple in Tainan City. Not Taiwan holds dragon boat competition on May 5th each year in Lunar Calendar.

 
Ryukyu

In Ryukyu, there is a custom of painting dragon boats and putting up a piece of human-figure paper, known as “Shi-Shu” for exorcism. People also put up dragon boat mold and some figurines of local people wearing Ryukyu suits, playing instruments, drumming, and dancing in traditional Ryukyu dances.
 

Reference material

http://zh.wikipedia.org/wiki/端午节
http://big5.huaxia.com/zhwh/whrd/whrdwz/2009/05/1441152.html