the boats don't do a return trip; it's just one-way. .   Google Santorini Port to see how many ships will be in port with you, plus their arrival/departure times, and # of pax.  That information will help gauge the situation but it's not a guarantee.  ie our ship (2800 pax) arrived at 1:30pm and the only other ship (2700) was 7am-4pm.  I assumed the other ship's pax would have gone to Fira hours earlier so there would be no line for us at the cabl car. WRONG!  We stood 2 hrs. The