one day in Santorini

You'll be tendered ashore below the main village of Fira. Take the cable car up the cliff into the village. PLEASE DON'T RIDE THE POOR ABUSED DONKEYS!! When you exit the cable car building immediately turn left, away from the caldera, and walk to the end of that lane. Turn right and immediately on your left is a short flight of steps down to another lane. Go down the steps and walk out to the main road. Oia is uphill to the left 7 miles. You can rent a car right there or maybe flag down a taxi, or you can walk downhill to the right about 1/4 mile, past the main square where the outdoor cafes are located side-by-side, to the taxi office, which is just before the bus terminus.

But if you sign up for the cruise ship's land tour you'll be tendered ashore to a different port where tour buses will be waiting to take you around the island, Oia included.

Thanks, Lee. Buses are easy in high season, but I can't confirm whether or how often they run in October. If you see a bus ready to depart, either to or from Oia, you can buy the ticket onboard (1.60 euros each way, per person).

The buses run all year long. By October they're most likely back on the winter timetable, meaning no more than once per hour and they'll stop running by 8pm at the latest.

We were in Santorini on a cruise last October around the third or fourth week of the month and took the bus from Fira to Oia and back. Anyone can point you to the bus area. Ask again, get on that bus, and a fellow walks the aisle taking money for tickets as you travel. I don't recall the frequency of the schedule but it was not a problem and we had enough time in both towns for a decent visit.