Hi…. You will know which ports you are visiting and I would suggest that you study them by visiting the RCI web pages showing the tours that the ship offers, the different ports web sites with a view to "tourism" and the ports pages of cruise critic. This will give you a very good idea of what to see and do and also the prices that you can expect to pay. Going ashore on a DIY excursion can be daunting at first but if you can get some friends to go with it will be great and far less expensive than the ship's excursions. May I just say that I hope you find Europe as hospitable as we found Walvis Bay. We have fond memories of Dune 7 and The Raft Restaurant where we made some excellent friends......Good Luck.....Nei.
You picked a great ship we've done 3 excellent cruises on the Navigator. We always cruise with RCI and mix and match re excursions. They ARE over-priced but generally of good quality and if you are looking at making a full day of it the ship will wait for a late to return ship's excursion BUT they will leave you if you are late doing it yourself. For example we had only a morning in Gibralter and saw almost everything on a RCI excusion as did 2 people doing it themselves they even saw The Legend of the Seas leaving port without them on it. The best bet is post some ports and excusion ideas as a question on this site and someone will have the best specific answer.... Enjoy the Navigator... Simo.