A Comparison of Methods for Locating, Tracking and Quantifying Submerged Oil Used During the T/B DBL 152 Incident

Abstract

A variety of methods and equipment were employed during the response and long-term monitoring phases of the DBL 152 incident to locate, track and quantify the nearly 2 million gallons of low-API gravity oil that sank in the western Gulf of Mexico approximately 30 nautical miles off the coast of Cameron, Louisiana. Methods and equipment used to survey submerged oil included: divers; stationary snare sentinels; chain-weighted snare drags using devices known as vessel-submerged oil recovery systems or V-SORS; remotely operated vehicles (ROVs), underwater video drop camera, sled-mounted towed video, side-scan sonar and Rox-Ann sonar. This paper will describe each method and associated equipment and its specific application to submerged oil detection and assessment for this incident. It will also explore the evolution and refinement of approaches used throughout the course of the response and the underlying rationale for these changes. Guidelines and relevant considerations for selecting among these methods will be suggested. Finally, strengths and limitations of each approach will be discussed with the goal of capturing and communicating the lessons learned so that future submerged oil response efforts may benefit from the practical experience gained during the DBL 152 response.