On cruise ship stopping for a day in Cobh, Dublin and Belfast

From our 2014 Princess cruise, I can offer these suggestions:
- Cobh: We did not book a shore excursion as the ship docked alongside the train station, a small Titanic Experience museum, and a very easy short walk from the town center. An uphill walk to the beautiful St. Colman's Cathedral and a tasty fish 'n' chip lunch nearby were all we needed for an enjoyable (albeit rainy) day in Cobh. Note: There was a small passenger train/tour around town for a fee if one wasn't able to manage the hillside walk. This small town was very tourist-friendly!
- Belfast: As the ship docked in a large industrial zone with no foot traffic, we booked a combo City Tour with a stop at the wonderful Titanic Belfast museum. This is a very popular new attraction with timed ticketing and a limited number of hand-held multimedia guides so we were glad we had pre-booked a shore excursion (allowed us to skip the queue and enter at the time our tour guide had reserved). The museum was large and hands-on providing more details than you would ever want to know about the Titanic - extremely well organized! The City Tour included a drive through the beautiful city center as well as the "troubles" area of Belfast (murals). If memory serves me, there may have been a shuttle bus from the ship to the city center for independent exploring, but then it was likely a taxi ride to the Titanic Belfast museum. Friends from the cruise enjoyed a shore excursion to the Giants Causeway (World Heritage Site) which I would have liked to have experienced too - perhaps next time!
As I have only visited Dublin on a 2-day business trip (our ship did not stop there), I am not able to offer any suggestions re the cruise ship experience - charming walkable city center was my impression. Hope this helps.
Mardan

Thank you, we will be on a Princess cruise also.