Longboat racers just after crossing the finish line at Krabi, southern Thailand

Part of the crowd that gathered in boats to watch the traditional longboat racing at Krabi

Longboat racers at Krabi waiting for their heat to start

More racers between heats at Krabi

Part of a crew of racers at Rasi Salai, northeast Thailand

Crews waiting between heats at the competition at Rasi Salai, Sisaket Province, in northeast Thailand

The boats themselves are usually hewn from a single tree trunk. Some have crews of 50 or more men, as seen here.

Promotion of harmony and unity through the teamwork required at all stages of the process, including building the boat itself, practicing, and competing, is seen as a primary goal of the discipline today.

Most of the races take place around the end of the rainy season, in September or October, when river levels are at their peaks.

Most of the photos in this gallery were taken at competitions for the King's Cup held at Rasi Salai, on the Mun River in Sisaket Province, northeast Thailand.