The shallow part is 4 feet. This depth makes the flip turn easy and possible. The pool is deeper, 6 feet, than Jing's height 5 feet 9 inches. In this Worthington pool, when Jing makes turns, Jing knows that he will not hit the bottom of the pool. Therefore, he dares to make the turn.
Batman: The Animated Series. Episode: Joker's Favor. Dr. Harleen Francis Quinzel, also known as Harley Quinn, first appeared in the Batman: The Animated Series episode Jokers Favor (episode #022, original air date: September 11, 1992) where she served as a humorous female sidekick to the Joker.
Her origin was revealed in Dini and Timm's Eisner Award-winning 1994 comic The Batman Adventures: Mad Love. Harley Quinn was Dr Harleen Quinzel (seriously), a psychiatrist interning at Arkham Asylum who fell in love with the Joker which - professional ethics aside - is not something a sane person is likely to do.