If you book a fly-cruise then yes it is, if you book cruise only then no it isn't. If you book cruise only then you also do not get transfers and have to make your own way to/from ship.
Further to the answer, a lot of travel agents will do a package for you, but you have to know that it is not a ships package, but one put together by the travel agent. So while you will get the flights & transfers along with the ship's cruise, you will need to make sure that you get to the cruise port at least the day before & have at least one night in a hotel, as any flight delay & the ship will not wait, unlike a package organised by the cruise company. A travel agent will be able to do all of this for you, with ease.