Santorini- transfer to Oia

Our ship gets into port at 7am, another at 8am and a 3rd at 9. We are hoping to get off early to get to Oia. My understanding from reading posts on various sites are there are 2 or 3 companies that do the ferry to Oia, then bus back to Fira. Anyone know if they take credit card on the dock? Ageantraveller was 1 listed and they do sell online, but it looks iffy to me as it shows they always have 100 available to sell and no specific time. Also read a poor review from them as of last week on tripadvisor, but couldn't ask the person what time they went (said long time at sea waiting to dock).

Any help is appreciated! Thanks!

After getting off the tender (around 11am I think) we looked for the ferry companies. There were two places that I noticed and it looked like they were offering the same deal for the same price - I suspect both "companies" are actually one and the same. We stopped at the first place we came to and, since they claimed to have a ferry leaving in five minutes, we bought tickets. We paid cash but I'm fairly certain you could use a credit card. The fare included bus transfer to Oia town and then to Fira. The ferry was there waiting and it did indeed leave very quickly.

There is a short, steep climb up to the buses at the Oia wharf, but it was manageable. We arrived in Oia town around 12 noon. The last bus to Fira left at 2pm so that didn't give us much time in Oia and it was very crowded. It's certainly worth visiting but I'd recommend getting a much earlier tender ashore if you can. Our ship didn't depart until 7pm so I was a bit surprised that the last bus to Fira was so early.

The bus to Fira stops on the main road outside Fira and it is about a 10 minute walk to the cable car. At that time of day, the day we were there, it took 1.25 hours to get on the cable car. The other options to get down to the tender wharf are to ride on a donkey or to walk down the donkey trail (several hundred steps).

Note: there were two cruise ships in port that day. Ours (Royal Princess) and a Royal Caribbean ship of a similar size.