Santorini was a mess, so take a ships tour which tenders you to other port where buses are waiting. Only ships tour use other port, you will take cable car back down but the wait will be shorter. Alternative is from where the tender everyone else where cable car is you can take a boat to Oia wither bus back ti Fira included for 30 euros per person. NCL tender process was very slow, ships tours had priority. They were still calling tender numbers 4 hours after anchoring.