Why are dragon boats buried in the riverbed silt immediately after the race?
A truly good dragon boat is preserved by sinking it to the bottom of the river. Traditional Guangdong dragon boats are mostly made of ironwood (also known as juniper wood). This wood has a counterintuitive characteristic—it lasts a thousand years when dry, ten thousand years when wet, but only six months when neither dry nor wet. When fully submerged in water, the fibers of the ironwood swell with water, and the lignin is extremely difficult to decompose in an anaerobic environment. It is impervious to insects and fungal decay, and actually becomes stronger the longer it is submerged. Once exposed to alternating periods of dryness and moisture in the air, it will crack and warp within a few months. Therefore, the standard procedure for veteran dragon boat operators when bringing the dragon boats to a close for the Dragon Boat Festival is to fill the boat with water, tie it with stones, and let it sink steadily into the riverbed silt.
