OK finally got time to check Lance's answer to this question: What is the total amount of variable ballast in pounds that a Balao submarine has at its disposal. (i.e., pump out or in to surface or in emergency)?
Lance was correct 231,640 lbs (115.82 tons of sea water)
Forward Trim - 24.31 Tons of sea water
Fwr WRT = 4.94 tons
Aux Ballast 1 = 30.77 tons
Aux Ballast 2 = 30.77 tons
After Trim = 19.97 tons
Aft WRT = 5.06 tons
total = 115.82 tons x 2,000 lbs = 231,640 lbs
231,640 lbs / 8.56 = 494,350.47 gallons of sea water if anyone cares
1 gal of sea water weighs 8.56 lbs due to sea water being about 2.5% heavier than fresh water (approximately)