By Ferry: Istanbul is becoming an important port for cruise vessels also. In the recent years, many cruise companies are including Istanbul to their list of visiting ports. This is making Istanbul an interesting stop for Cruise passengers.
Cruise passenger terminal in Istanbul is located at Sali Pazari / Karakoy. Karakoy is just across the Golden Horn of famous Istanbul peninsula. Most of the questions are arising concerning the location of the Ferry terminal, I assume below map will give you some idea.
In Istanbul the Cruise terminal at Karakoy, hosts cruise vessels that are heading to Mediterranean ports, such as Athens, Dubrovnik, Civitaveccla (Rome), Venice and others. You can also take passenger ships to black sea ports of Ukraine, Russia and Romania. You should mind that Cruises are not regular ferries but you can take a package tour.
Ferries to Black sea ports mainly operates during summer time. Destinations are Odessa, Yalta, Sevastopol, Kherson, Efpatorya, Novorossisk and Konstanz on the Black sea and their schedules do changes very frequently, however I made the best possible as follows. Fery costs vary from 80 to 200 USD one way.