Covers guidelines for the reconciliation of marine cargo quantities. These guidelines are intended to provide a basis for analyzing and reconciling the quantity differences (gains/losses) resulting from marine custody transfer movement(s) of petroleum and petroleum product cargoes. As such, the guidelines are complementary to, but do not replace, normal inspection procedures. The shipment of petroleum or petroleum products by marine vessels often result in a difference between the load port (Bill of Lading) and discharge port (Outturn) quantities. The objective of cargo analysis and reconciliation is to determine if a marine petroleum shipment results in excessive gain or loss, and if so, to identify the reason (s) for volume differences in an effort to correct petroleum measurement problems. Describes the primary steps for marine cargo analysis and reconciliation. Those steps are the following : (a) Voyage Data Collection; (b) Voyage Data Analysis; and (c) Voyage Summary and Reconciliation.