Here's an interesting story where a council member from Dana Point City, California tried to contact Royal Caribbean about seeing what it would take for their cruise ships to stop in their city as a port of call. Lara Anderson contacted Royal Caribbean to get an answer after questions were raised by the Pacific town on the viability.
Christopher Allen, Director, Deployment and Itinerary Planning for Royal Caribbean International, Celebrity Cruises & Azamara Club Cruises responded to the request and cited these issues that Royal Caribbean uses to determine what ports to stop at: Location, marketability, tour/shore excursion offerings, port fees, politics and regulations.
Of more interest are the tough requirements a city needs to be able to handle Royal Caribbean's large vessels.
The port must have the infrastructure to handle our ships. We do not have any small ships. Most of our ships are actually too big to fit through the Panama Canal. As a result, only our ‘small’ ships are over on the West Coast of North America. But even our small ships average about 2000 guests and are about 290 meters in length. Our strong preference for all ports is to be able to dock. Most, but not all, of our ships carry tenders and can tender guests into a port if the distance is below 1.5 miles. However, we try to avoid tender ports as it can create lines, weather disruptions and lesser guest experience. That said, if the appeal is strong enough we will still tender.
It looks like Dana Point City wont be a port city anytime soon short of a major port overhaul, but nonetheless, it's an interesting look at what it takes to be a port destination.