Marina Sirtis beat 19 other actors, 17 of them actual Russians, at the audition. Her Russian accent was so good that after the first take she was asked to tone it down so she could be understood.
Kurt Russell, who played Jack O'Neil in Stargate (1994), visited the set during filming of this episode.
The title "Watergate" was initially a joke before becoming the official episode title.
The idea of a story set on an underwater world was conceived in planning for season 2, but the production company did not have the technical capability or the budget for the special effects at the time.
The transport aircraft they board at Kuybyshev Airbase in Siberia was actually a USAF C130 belonging to the California Air National Guard sitting on the tarmac at Boundary Bay Airport just south of Vancouver, BC.