Factual error: Joe Jackson batted left-handed in real life, not right-handed as Ray Liotta portrayed. He also threw right-handed and not left-handed like it shows when Kevin Costner is hitting him fly balls to left field.
Factual error: At the end of the film, when Ursula has Triton's powers, she creates an enormous whirlpool that pulls wrecked ships off the ocean's floor. Prince Eric boards one of the ships that is being swept along with the whirlpool's currents, then turns the rudder hard to steer the ship into Ursula. Not possible - in order for the rudder to change the course of a ship the vessel must be moving faster than the current.
Factual error: After their parents give up looking for the kids, there's a "time passing" scene showing the lit attic window from the outside of the house, in which the night grows lighter until it's morning of the next day. But the moon in the picture doesn't move. How can the moon stand still if time is passing?
Factual error: Nobody can fall onto a car and come away with few injuries. Yet Colleen Camp does with a sore back and briefly wears a neck brace.