The article discusses the development and use of the Miniature Autonomous Plume Recorder (MAPR) by the Pacific Marine Environmental Laboratory (PMEL) for studying hydrothermal vents and their impact on ocean processes. The MAPR is a small, self-contained instrument that can be deployed in various ways, including on autonomous underwater vehicles and remotely operated vehicles. It is equipped with sensors to detect hydrothermal plumes and has been used for global deep-sea exploration, mapping volcanic eruptions, monitoring turbidity in lakes, and mapping methane seep sites. The MAPR program supports collaborative projects and is currently undergoing a redesign to enhance its capabilities.