Plot

ἐν τῷ ἐνδεκάτῳ μαθήματι ἐμάθομεν ὅτι, χρήματα νῦν ἔχοντες, τῷ τε Δικαιοπόλει καὶ τῷ Φιλίππῳ ἔξεστι εἰς τὴν Ἐπίδαυρον ἀποπλεῦσαι (ὡρμήσασθαι, ἐν νηὶ πορεύσασθαι). (All 1st aorist infinitives to express the idea of setting out, simple action: the emphasis is on being able to travel to get help from Asclepius, not on the duration, the progress of the travel itself)

So what happened next?

What did the Greeks always do before setting out on a journey, before undertaking anything in fact? (Remember lesson 2b, before seeding, lesson 8b before leaving home)
Who doesn't accompany Dikaiopolis and son to the Piraeus? Whyever not?
How did one get from Athens to the harbour at Piraeus?
What sort of a road was that? And what about the traffic on it?
Why did they stop, and why were they then at a loss about what to do?
Who turned up, like a good guardian angel?
So how did they finally finish the trip to Piraeus?