The phrase "astern to" is not a complete sentence and is not grammatically correct.
It is also not a commonly used phrase in written English. It is possible that "astern to" is intended to be a prepositional phrase, but it would need to be used in a specific context to make sense. Example: "The ship sailed astern to the harbor." In this sentence, "astern to" could mean that the ship was sailing backwards towards the harbor. However, it would be clearer to say "The ship sailed backwards towards the harbor" or "The ship approached the harbor from astern."
The Americans slipped behind the committee boat with Prada just astern to take the start by seven seconds.
While standing watch on the bridge during the early hours of that day, one of the officers of the Ramapo saw, in the moonlight, a great wave rising astern to a level above an iron strap on the crow's-nest of the mainmast.
Captain Salmond rushed on deck and ordered the anchor to be dropped, the quarter-boats to be lowered, and a turn astern to be given by the engines.
For when the sleek, fast maxiboats ran out of wind, the smaller vessels astern continued to make miles in a private pocket of air.
Another was the ability to go astern at full power without needing a separate reverse turbine to do so, simply by reversing the electrical polarity of the motors.
He debated firing into her, but decided to hold fire and press on to the French centre, where he eventually came to anchor astern of Orient, close to Bellerophons original position.
It was necessary for the ship to steam at full speed astern in order to avoid a collision with.
With the Marine aircraft aboard, Lexingtons flight deck was very congested and he decided to reverse the phase of the ship's electric propulsion motors and steam full speed astern in order to launch a new CAP and then swap back to resume forward motion to recover his current CAP.
He then ordered the two surviving ships of the 3rd BCS to take position astern of New Zealand, while slowing to 18 kn and altering course to the south to stay close to the Grand Fleet.
With Nymphe and Melampus still too far astern, and unable to catch Résolue himself, Strachan engaged Engageante and after 105 minutes of fighting, forced her to surrender, while Résolue made her escape.
He then ordered the two surviving ships of the 3rd BCS to take position astern of New Zealand, while slowing to 18 kn and altering course to the south.
