Compared to the overall story outlined in Acts, it seems that this chapter has only to say that God wanted Paul to arrive in Rome and, therefore, saved him from the shipwreck: it seems little to justify this detailed story, we will therefore try to grasp other aspects of it.
The story begins with: «When it was decided that we should sail for Italy». This means that there was also Luke on the ship, who presumably was there as Paul’s assistant, and since Luke saw God at work on that trip, this itself is a good reason to tell the story.
The manner in which Luke recounts the facts allows him to make a close parallel with Joseph who, like Paul, found himself unjustly imprisoned (Gen 39:20; Acts 26:31), but was immediately well-liked by the jailer (Gen 39:21; Acts 27:3), receiving from God the solution to serious problems concerning the community (Gen 41:25ff; Acts 27:21-24), being prompted to assume responsibility for conducting operations (Gen 41:41; Acts 27:31-38), so God’s blessing was enjoyed by all (Gen 42:6; Acts 27:44).
Paul, unlike Joseph, would remain formally a prisoner, but in essence free, since he could evangelise Malta (28:1-10), stay seven days with the brothers of Puteoli (28:14) and wait for the trial not in prison, but in a home and being able to receive all (28:16,30).
Paul gave a first warning with modesty (27:10), but the centurion trusted more the expert, the owner, the majority and an encouraging fact, represented by a slight wind in the right direction (vv. 11-13): who of us would not do as the centurion did? Paul had to intervene again and with more authority, with the risky announcement that an angel of God had spoken to him and that, as God wanted him to appear before Caesar, he would save everyone, even though the ship would have been lost for not having listened to him the first time (vv. 21-25).
The fulfilment of the prophecy, however, would not have been automatic and outside the freedom of those to whom salvation had been promised. Indeed, the emergence of gestures of distrust towards the promise of God made Paul say that (prophecy or no prophecy), if they would not manifest concretely a confidence in the word that God had addressed to them, that promise would not have been realised. The soldiers understood the message well and deprived themselves of the lifeboat, which represented the “plan B” guarantee, in the event that the “plan A” announced by Paul would prove ineffective (vv. 30-32).
Another “gesture of faith” that Paul invited to make, setting an example, was to eat (vv. 33-38), in order to be ready to make the personal effort necessary to reach salvation on the beach.

The 276 people on board were all saved: was it by faith or by works? By decree of God or by making use of their freedom? I believe that the whole Bible teaches us that these are wrong questions, that arise from our limited point of view, because when God works, He does it with complexity (which brings together prophecy and freedom) and not in obedience to one or the other theological scheme, within which we may be tempted to lock the Bible up in, which instead reflects the complexity of God.
A secondary aspect of this story is that it makes one perceive an “internal evidence”, and so that this is a lived chronicle and not a fictional story. Therefore, it is as if with it Luke had placed a “stamp of authenticity” that enhances the whole work.
We will dwell separately (Further Insight n. 16) on a possible purpose of Luke in telling this journey in detail: to make the Romans understand how much God wanted Paul to preach in Rome.