Hall invented iron bilge tanks for ships, adopted by the navy, and "Hall's patent anchor".

Bilge water: Water from the ship's bilge tank that contains engine oil and sludge.

It dived by allowing water into a bilge tank at the bottom of the vessel and ascended by pushing water out through a hand pump.

Hazardous waste: Cleaning chemicals, paints, solvents and dry cleaning chemicals that find their way into the gray water source or the bilge tank.