Your design can include a number of
internal tanks, which can be full or
partly full, with a fluid of any density. The tanks can be of any shape,
within the frames+lines convention of the program (Tanks are formed between
lines extending only part-way along the hull). Hullform can generate
automatically a rectangular tank, one "mirroring" a tank on one side
of the hull, or one fitting closely within the hull's outer surface.
When partly full, the "free surface effect" of the tank is properly represented.
Along with this feature comes a range of other facilities, such as tank calibrations and hydrostatics summaries.
The hull shown here is an actual design by the Western Australian naval architect Gavin Mair. The lines drawn inside the hull show locations of several internal tanks, whose full properties Hullform can analyse at the expenditure of only a few mouse clicks.
For even more sophisticated tank reporting, you can use the power of Hullstat. This provides almost total control over any hydrostatic report format.