barnest2 said:
I'm sold. Downloading it now...
Why are my immediate memories of Inkscape along the lines of "I got what I paid for." (free) and "That was a waste of time downloading and installing, where's the uninstall?"
I recall it being exceedingly non-intuitive and lacking features that would have put it ahead of simply working with Paint for quick drawings.
Anyway, Sketchup is also free, pretty low easy learning curve with excellent tutorials and once you're done laying out the plans in 2D you can spin it up to 3D without much more work. imo of course.
Key is to find something that works for you and learn it well

Inkscape didn't for me but might well for you
That said, my best bit of advice for the 9,000ton cruiser deckplans is... don't
I've done (completed) a couple (and unfinished several) large ships (multi Ktons) and they can be a major pain for little gain. If you do I suggest starting with some key small areas and a general idea of the size and placement of the whole. Work the small areas into the whole as needed. And don't sweat the details too much
I generally start with the old architectural basic of balloons. Create roughly scaled and shaped areas/sections (bridge, engineering, quarters, cargo, whatever big elements you have - ignore fuel and armour for now, fill it in between and around for shaping the hull as desired) in approximate locations and check that for flow and function. Develop more specific measurements from that once satisfied with the rough guide.