MEMBER REVIEW #1: The first part is about living in an underwater habitat for multiple day, think Sealab. It was ok but the next two parts were fascinating. Part 2 deals with jelly like creatures living somewhere between the depths and the surface of the ocean. (It varies by time of day) Part 3 deals with cold seeps and the life on them. Superheated hydrothermal vents aren't the only game in town. I wound up watching parts 2 and 3 several times. MEMBER REVIEW #2: This Discovery Classics video has 3 hour-long episodes about marine research. One details an expedition aboard an undersea research facilty in a coral reef, upper level research. The second is about a diving expedition in the mid level depths, and the last is about a deep sea submersible in a trench. These programs are professional and well done. They are more high school level science, but are worthwhile watching.