boom down meaning in English

将下移
摄像机下移

I passed the line around one of them right on the edge of the cut bank , but there was a stiff current , and the raft come booming down so lively she tore it out by the roots and away she went
我把缆绳套在那凹岸旁边的一颗小树上。不过正好有一个急流，木筏猛地一冲，就把小树连根拔了起来，而木筏也就往前漂去了。
The whooping went on , and in about a minute i come a - booming down on a cut bank with smoky ghosts of big trees on it , and the current throwed me off to the left and shot by , amongst a lot of snags that fairly roared , the currrent was tearing by them so swift
大约一分钟光景，我突然撞到一处陡峭的河岸上，但见岸上一簇簇黑黝黝鬼影森森的大树。河水把我一冲，冲到了左边，河水飞箭似地往前直冲，在断枝残桠中一边咆哮着，一边夹着它们朝前猛冲。