Right of way runs or rapids

In going through a run or rapid the vessel first in shall have the prior right of way. If several vessels arrive at a run or rapid at the same time the down-coming vessel shall have the prior right of way. All motor boats when entering the run and at frequent intervals while in the run shall give sound signals. In any place other than a run or rapid where natural obstructions exist the vessel going up-stream shall give way to the vessel coming down-stream, provided always that where there is no risk of collision one vessel may pass another in a run.