When first swimming with the Mervanans, Webby mentions "Look at this stuff, isn't it neat", referencing that line from the song "Part of your World" from The Little Mermaid (1989).
After 3 episodes in a row with the short intro, this is the first episode to play the full version of the Season 3 intro, revealing that Della is included in the scene in the treasure room where the dragon appears and blows out the torch in Scrooge's hand.
Alethia is voiced by Hynden Walch, and happens to be friends with a laidback, green-colored vegan character voiced by Greg Cipes. This is a callback to the Teen Titans characters Starfire and Beast Boy, who have the same respective voice actors.
Della Duck is revealed to suffer from ichthyophobia, which refers to fear or disgust towards fish and is the reason she is the only one to primarily remain behind with the submarine.
The eponymous harp in this episode bares a slight resemblance to the one seen in the episode "Raiders of the Lost Harp" in the original series, only having brown feathers and purple hair rather then white feathers and blonde hair. Much like that episode, the harp seen in this one is used as a lie detector and says "fibbing" whenever someone lies about something.