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If you treat Waterfall as a precedent, there are only 3: Surskit, Beartic, and Keldeo.
Otherwise, there are lots more than I expected, aka anything that doesn't look like it's "built" for underwater speed, such as Goldeen and Staryu and Horsea
Description for Waterfall: "The user charges the target at an awesome speed."
Description for Aqua Jet: "The user lunges at the target at a speed that makes it almost invisible."
I see no difference, especially with the likes of Oshawott getting it.