It would be easier to just ask for the base speeds of the ships, instead of the hidden value you highlighted which isn't even legal to extract from game files anymore I think. You could try dig up LordKelvins old thread from the old forum section, think he listed every USN ships 'c' value.
EDIT: Infact I even went and dug it up for you.
Values are Iowa 10.7267, Montana 13.45, Nebraska 15.5635. Though these might be out of date.