large ships are typically launched into the water when the hulls are completed but that doesn't mean all of the construction work is finished usually there is still a significant amount of work to be done including finishing the interior of the ship building the superstructure etc take a look at image sms seydliz under construction jpg for example you can see the ship is already in the water but a significant amount of work is being done to the superstructure you can also read ship naming and launching for more information about launching hope that helps