Yes, but aren't the steam generators closed loop? If you keep blowing out steam, you need to replenish water. That water must be stored on board or extracted from the sea water. I doubt that it is a good idea to use sea water in the generator; higher corrosion and all that jazz. The advantage of an electric system, is no consumables wasted, save fuel for the initial generation, which you would have used anyway.
Nuclear aircraft carriers have large scale desalination (distillation, aka "flash evaporator") plants, some capable of producing 400K gallons of distilled water each day, in excess of shipboard daily water needs.