1999 | 7 Episodes

Season 0 of Sealab 2021 premiered on November 30, 1999.

2000 | 10 Episodes

Season 1 of Sealab 2021 premiered on December 21, 2000.

2002 | 11 Episodes

Season 2 of Sealab 2021 premiered on April 7, 2002.

2003 | 12 Episodes

Season 3 of Sealab 2021 premiered on May 26, 2003.

2004 | 11 Episodes

Season 4 of Sealab 2021 premiered on June 20, 2004.

2005 | 8 Episodes

Season 5 of Sealab 2021 premiered on March 6, 2005.