Dive 04 of Seascape Alaska 3: Aleutians Remotely Operated Vehicle Exploration and Mapping expedition took place on July 18, 2023. During the dive, we explored Aleutian arc cold seeps (Sanak seeps) that were discovered only two months earlier during the Seascape 1: Aleutians Deepwater Mapping expedition. The dive at 2,100 meters (6,900 feet) water depth was carried out using NOAA Ocean Exploration’s remotely operated vehicle (ROV) Deep Discoverer (D2). Exploration of the Sanak seeps resulted in the discovery of bubble plumes, gas hydrates, thousands of tubeworms, patches of chemosynthetic clams, and special rocks produced by microbial processes.