Reason of congestion（等泊原因） 

1) Vessel ; Many vessels are waiting for discharge.
（由于等泊卸货的船多。）
2) Weather ; Port closed due to dence fog, strong wind, heavy rain, snow, and etc.
（由于大雾，大风，大雨等天气原因）
3) Others ; Channel closed due to sunken vessel, collision, navy drill, and etc.
（由于沉船，碰撞，军事演习等原因导致航道关闭等特殊情况。）