Hanna-Barbera Productions Sealab 2020 Sealab 2020 was a cartoon series produced by Hanna-Barbera Productions and broadcast on NBC from September 9, 1972, to December 2, 1972, on Saturday mornings. The series was created by Alex Toth who also created such other Hanna-Barbera cartoons as Space Ghost and Birdman and the Galaxy Trio. A total of 13 episodes were aired, with two episodes remaining unaired. As with most Hanna-Barbera series, the show was in occasional rotation on Boomerang, the TV chan