The ship that picked up Arthur and Ford happens to be the Heart of Gold, the ship that Zaphod stole in Chapter 4. Except to Arthur and Ford, it looks like Southend, which is a popular seaside vacation spot in England. No word on whether Southend paid Douglas Adams for this bit of product placement.
Actually, everything looks weird for a while: the sea remains stationary and the buildings wave up and down; Arthur loses a few limbs; and Ford turns into a penguin. No, really. As Arthur says to Ford, "you're turning into a penguin. Stop it" (60).
At the same time, an announcing voice seems to be giving probability measurements, which doesn't help anyone (or give any secret phone numbers). But the voice does welcome them to the Heart of Gold.
Ford explains to Arthur that they're on a ship with the Infinite Improbability Drive. And that means that we're probably in for another digression. But wait, what's this? The chapter is already over? But we wanted to know about the Infinite Improbability Drive. Now we'll never know about it, we guess.