seaway
sea lane
ship route
trade route

It would take a century for peace to come to the sea lanes around Sardinia.

How did it affect the sea lanes and the war itself?

He did not add how vital it was to keep some control of the sea lanes.

The episode is also likely to add to concerns about the crowded sea lanes around Europe.

One effect of the shooting is that for now the sea lanes are quiet.

"We will never allow our sea lanes to be turned into oil pipelines."

They'll get into the sea lanes and if they do.

And he was not in a sea lane for ships.

They would make far better time keeping to the sea lanes, where it was not necessary to climb.

But there are obviously different ways you can try to maintain access to sea lanes in wartime.