‘And on the second day we came to Puteoli, where we found brethren, and were entreated to tarry with them seven days. And so we came to Rome.'
Sailing time was good and on the second day they arrived at Puteoli which competed with Ostia as the main grain terminal for Rome. There they found a group of Christians and were heartily welcomed among them for ‘seven days', a period of joy and bliss. This meant that they could spend with them both the Sabbath day and the first day of the week, celebrating together the Lord's Supper. So having started off with a seven day stay at Troas so long ago (per the parallel) at the commencement of his ‘journey' (to Rome via Jerusalem) he now experiences the same thing at the end. All is well. God has not changed. A recently discovered Christian chapel at nearby Herculaneum may well once have been a venue for some of these Christians who met Paul.
Luke does not explain how this seven days was managed, for after all Paul was a prisoner. But Paul was now the hero of the shipwreck and may well have been given some licence. It may, however, be that on arrival at his destination the centurion had some formalities to complete which necessitated a seven day wait. Possibly arrangements had to be made for the disposal of the prisoners. This was the Rome terminal. Or possibly their papers had been lost at sea, necessitating further instructions
‘And so we came to Rome.' This is not a travel description, but a triumphant eulogy. ‘This is how we came to Rome, into the bosom of believers.' They were in fact not quite there yet, but to these weary travellers it seemed like a homecoming at their first real landing on Italian soil. To them Puteoli in Italy spelt Rome. (To arrive at Ostia or Puteoli signified Rome to all sea travellers. They were Rome's grain terminals). This would be how they would ever remember their arrival in ‘Rome'.