I. INTRODUCTION II. VESSEL PROSECUTIONS PURSUANT TO APPS A. The Generation and Disposal of Oily Wastes on Board Oceangoing Vessels B. Overview of MARPOL and APPS C. The Elements of [...], The U.S. Sentencing Guidelines contain provisions that can enhance a defendant's offense level to one that authorizes jail time, if the court finds that the offense 'resulted in' repeated discharges of a pollutant to the environment or 'otherwise involved' a discharge of a pollutant. Whether or not a defendant gets jail time in federal environmental crimes cases often depends on the applicability of these Guideline enhancements. However, since the term 'environment' is not defined in the Guidelines, it is not clear whether the term includes discharges of pollutants outside of the jurisdiction of the United States. In United States v. Abrogar, the Third Circuit Court of Appeals had the opportunity to resolve this issue in the context of a vessel prosecution. In this case, the chief engineer of a large, foreign-flagged cargo vessel ordered his crew to discharge oily wastes to the ocean and then arrived into port in New Jersey with a document called an Oil Record Book (ORB) which he had falsified to conceal the discharges from the Coast Guard. Since the oily discharges were to waters beyond the jurisdiction of the United States, the government charged the chief engineer with maintaining a false ORB in a U.S. port in violation of the Act to Prevent Pollution from Ships (APPS). The district court sentenced the defendant to a jail term of a year and a day based on a finding that the false ORB resulted in repeated discharges to the environment under the Guidelines. The Third Circuit reversed homing that the Guideline did not apply, because the environmental discharges were not relevant conduct or offense conduct under the Guidelines, since they occurred outside the jurisdiction of the United States before the vessel came into port with the false ORB. In doing so, the Third Circuit effectively precluded a sentence of jail time under the Guidelines for the defendant. This Article argues that the Third Circuit's decision was fundamentally flawed, because the discharges were a necessary element of the offense of the false document violation charged under APPS. The Article then explores other statutes and Guideline provisions available to authorize jail time in these cases. In so doing, the Article details many of the legal and sentencing issues that have arisen in vessel prosecutions.