Dennis R. McDonald in his article "The Shipwrecks of Odysseus and Paul" (New Testament Studies, 1999:88-107) gives imho the most satisfying explanation of the we-passages as a stylistic device in imitation of Homer's The Odyssey. In this work, the first person plural is used to indicate voyages to and from the Troad (the cities of Troy):
"Embarking (anabantes) at once, we put out (enekamen) into the broad sea" (Odyssey 12.401)
"Embarking (epibantes) on a ship of Adramyttium that was about to set sail to one of the ports along the coast of Asia, we put to sea (anekhthemen)" (Acts 27:2)
Cf. also: "We were sailing together on our way from Troy" (Odyssey 3.279). Later works also imitated the Odyssey's use of the first person plural to refer to voyages involving the Troad. Thus Virgil had Aeneas narrate his voyage to Rome: "We put out (prohevimur) from port [at Troy] and lands and towns faded from view" (Aeneid, 3.71-72), and McDonald cites similar examples from Lucian, Chariton, and others. Thus it is significant that the we-passages begin with a voyage from the Troad, specifically the town of Troas, a mere 10 miles from ancient Troy:
"We immediately sought to cross over to Macedonia, being convinced that God had called us to proclaim the good news to them. We set sail from Troas and took a straight course to Samothrace, the following day to Neapolis, and from there to Philippi" (Acts 16:10?12a).
In fact, the route of the voyage described here is precisely that in
Odyssey 9.39-40. The second we-voyage in
Acts also involved the Troad, in that certain people "were waiting for us
in Troas, but we sailed from Philippi after the days of Unleavened Bread, and in five days
we joined them in Troas, where we stayed for seven days (
Acts 20:5-6). The third and final we-narrative begins in
27:1-2 (quoted above) and it also has a link to the Troad; Adramyttium was a port city in the Troad at the base of Mount Ida, famous in the
Iliad as the gods' favorite lookout on Troy. The ship travelled "the ports along the coast of Asia," taking it through the Troad. McDonald shows that the we-passages in Acts, especially that of the third voyage, is heavily dependent on the
Odyssey with many parallel passages, common unique vocabulary, and plot motifs; the article gives many examples of these, especially relating to the shipwrecks of Paul and Odysseus. The use of the plural "we" is just one of these literary devices adopted from the
Odyssey.