The amusing underwater adventures of SEALAB 2021 continue in this fourth season of fun and frolics from the crew. Could it be possible to colonize the depths of the ocean so that humans could live there? That is the question they face as they traverse the ocean floor. Unfortunately the team are somewhat incompetent, leading to a series of misadventures that provide plenty of laughs. The fourth season is included here in it's entirety. Special Features: Audio: (unspecified) - English Additional Release Material: Alternate Endings - 1. "Legacy of Laughter" Deleted Scenes - 1. "Joy of Grief" Other: Best of Sealab/Sunken Treasures.