Belfast: Used cityandcausewaytours.com--Alister. Absolutely wonderful. Mercedes van was great with a PA system. There were 6 of us. Did Giants Causeway, Carrick-a-rede Bridge, Antrim Coast, Dunluce Castle, Belfast. Game of Thrones Hedges. A great great tour. Loved this area. There was a shuttle service provided by local authorities on a complimentary basis. The ship docked at Stormont Wharf and the port is located about 15 minutes drive from the city center.
Dublin: Used Garvan Rusche or dublintourguide.ie. Very knowledgeable in history. 5 hour walking tour for 6 of us. Would do bigger groups but we like to keep our groups to 6-8 people in all our excursions. We took taxi into Dublin. Was 20 Euros for 6 of us. It is about a 15 minute drive. You can also do Dublin on your own. The Princess shuttle was $8 pp each way which is why we took a taxi. You can walk around Dublin. There is a tourist center right by Trinity College and the taxi rank to go back to the ship is also right in that vicinity. We docked at Ocean Pier #33 in Alexandra Basin.
Edinburgh: Tender port and we waited an hour to get a tender back to the ship and it was 1 1/2 hours before the final tender departed from shore!!! Long, long wait. Also that is because the tide is in and they can't dock but 1 or 2 tenders at that time of day. We had a tour with Tours by Locals, the gentleman is retiring. He picked us up at port. I think I would take the transportation into Edinburgh and do the Castle with the audio tour and then walk the Royal Mile and perhaps see Holyroodhouse. You can do all this on your own. Go to the Scotch Whisky place by the Castle and do tastings. Our guide also took us to Rosslyn Chapel which was interesting. The ship docked at South Queensferry and there were a few shops there.
I bought the tickets for the Castle and Audio Guide before we left the U.S.A. The Castle was wonderful!! Probably allow about 2 hours.
Someone from Cruise Critic joined Friends of the Tatoo so we could get our tickets as soon as they were available. They were in Section 12, Row R, 38 pounds each. Easy in and out. Excellent excellent show!!
We had private transportation so we got back to the ship well before the ship's buses.
LeHavre: We had already done Paris and Normandy on previous trips so we just took a taxi (8 Euros) into town. I had printed out a walking tour and we followed that. We walked back to the ship. Easy time. The ship’s shuttle was $8 pp each way. Nice city.
Guernsey Islands: Tender Port. Took about 10 min. We took the bus, route 91, around the island. It cost 1 pound each. It was okay. No commentary. Two scenic stops. Took 1 hour and 40 min. The tourist center is easy to find—turn left off the dock and keep walking. Tourist Center is on the right. The bus stop is just past the tourist center by the church. Could have walked around in town or gone to the Military Hospital or Underground or Castle Cornet on our own.