The purpose of this standard is to provide a method for determining the small volumes of On-Board Quantity (OBQ) prior to loading or material Remaining On-Board (ROB) a vessel on completion of discharge. The standard applies only to quantification by manual gauging of small volumes on marine vessels prior to loading or upon completion of discharge. The OBQ/ROB material may include any combination of water, oil, slops, oil residue, oil/water emulsion, and sedimen, present in the vessel's cargo tanks, void spaces, and pipeline. It does not address clingage, hydrocarbon vapors, cargoes in transit, or cargo pumpability (refer to API MPMS Chapter 3).