"Any navigation hazards in the next six hours?"

And after dark, it presented our patrol boats with a navigation hazard.

You can't simply bury them in space because eventually they constitute a navigation hazard.

They're a navigation hazard for one thing, so they should have been one of the top items in my briefing.

The navigation hazard would also serve as a smoke screen to hide the activities on Erphano.

The island was a known navigation hazard for many decades and several ships were wrecked there.

It has already become a navigation hazard for many of our visitors.

It's a navigation hazard and its course is headed for an inhabited world.

We know the Lincoln struck what they're calling a navigation hazard at sublight speed.

We have it marked off with buoys, 'cause it's a navigation hazard.