Ship's emergency astern is an emergency measure ofpreventionofcollision from ships.
船舶紧急倒航是船舶航行中避碰而采取的应急措施。
2
This series of signal Light is used for vessels navigation signal at night. Its behavior is in agreement with 1972 International Marine Regulation for PreventionofCollision.
该系列号灯适用于船舶作夜航灯光信号，符合《1972年国际海上避碰规则》。
3
Helfand added that tracking an asteroid is just the first step. The next step is preventionof a collision with Earth.