55 Grk “to the sea.” Here ἕως ἐπὶ τὴν θάλασσαν (heōs epi tēn thalassan) must mean “to the edge of the sea,” that is, “to the coast.” Since there is no mention of Paul taking a ship to Athens, he presumably traveled overland. The journey would have been about 340 mi (550 km).
56 Grk “remained there”; the referent (Berea) has been specified in the translation for clarity.

In other versions

Then the brothers immediately sent Paul off on his way to the sea, but Silas and Timothy remained there.

The believers immediately sent Paul to the coast, but Silas and Timothy stayed at Berea.

Then the brothers and sisters immediately sent Paul away to go to the coast, but Silas and Timothy stayed on there.

The believers acted at once, sending Paul on to the coast, while Silas and Timothy remained behind.

So then the brothers sent Paul away at once to go to the sea, and both Silas and Timothy remained there.

And then immediately the brethren sent away Paul to go as it were to the sea: but Silas and Timotheus abode there still.

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