Dr. Mike Perfit has spent over 45 years researching geological features of the sea floor and taken multiple dives with the unmanned robotic sub, Alvin. His experience with Alvin and exploring the seafloor are detailed in this article from The Conversation https://theconversation.com/scientist-at-work-im-a-geologist-whos-dived-dozens-of-times-to-explore-submarine-volcanoes-110472.