Taxi fares from the cruise terminal to the old city are between 10 - 15 Euros for 3 - 4 passengers. The position of your cruise ship will depend on a number of factors, from who gets there first to a question of size. Some of the smaller cruise ships may anchor outside the old city and use their own tenders to transfer to the old cities port, which is mainly now used by the local fishermen and the small number of locally organised boat tours.
There are lots of things to see, but there are also hidden gems. For those who do not wish to travel into the old city, you can travel to the north end of the cruise terminal and look at the huge Franjo Tuđman Bridge. This soars above the cruise terminal. There are also hidden bars and restaurants. At the south end by the small yacht marina, there is a bland superstore building, which looks rather grim, however, hidden on the top floor is a roof terrace bar and pizzeria. As this is kept away from most of the public, theres a real opportunity to relax and enjoy the views over the marina towards the cruise ships.
It is also worthwhile to walk along some of the many alleyways between the main streets. Although the cruise ships keep you supplied with more food you could ever wish for, try one of the small cafes in an alley. Squid is very popular together with a whole variety of seafood all freshly caught. The local bread is also very tasty. Prices vary, but seem to rise the closer to the main streets in the city.