Sentry Explores the Plume (IMAGE) U.S. National Science Foundation Caption Sentry criss-crossed the plume in deep Gulf waters 19 times to help determine its size and shape. Credit WHOI/Dan Torres Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.