- Mickey Mouse
- Donald Duck
- Ludwig Von Drake
- Giant Squid
- Minnie Mouse (as a mermaid; Hallucination)
- Daisy Duck (as a mermaid; Hallucination)
- Pinocchio (cameo)
- Geppetto (cameo)
- Chris Diamantopoulos - Mickey Mouse
- Tony Anselmo - Donald Duck
- Bill Farmer - Goofy
- Corey Burton - Ludwig Von Drake
- Russi Taylor - Minnie Mouse
- Tress MacNeille - Daisy Duck
- Joseph Ricci - Pinocchio
- This is the second episode of this series to be 7 minutes in length, the first being "Potatoland".
- This is the second episode to feature Ludwig Von Drake, the first being "Down the Hatch".
- Mermaid versions of Minnie and Daisy didn't have lines of dialogue in this episode.
- The mermaid illustration in Mickey's book is a Mary Blair painting produced as a concept during the production of Peter Pan.
- The submarine has many physical similarities to the Nautilus from 20,000 Leagues Under the Sea, with the diving suits, one of the windows, the pipe organ, and the giant squid.
- Pinocchio, who makes a cameo with his father Geppetto, properly has an Italian accent in this episode, while in his other appearances in the Disney universe, he has an American accent.
- The episode was originally titled "Submarine Voyage", which is named after the Disneyland attraction.
- The Giant Squid's screech is sampled from the Godzilla roar sound effect.
- The episode serves as the basis for an undersea scene in Mickey and Minnie's Runaway Railway.
- This is the final program aired on Disney XD UK before it shut down on September 30, 2020 due to a failed agreement with Sky UK and Virgin Media, with its content moving to Disney+
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