The "Scuba Steve" action figure in this movie is a fictional doll made up by Adam Sandler. "Scuba Steve" is based on a doll that Adam Sandler owned when he was a child, called Diver Dan. Diver Dan can be seen briefly in the intro scenes of another Dennis Dugan film, Problem Child (1990).
Cole Sprouse and Dylan Sprouse both lost baby teeth during production and had to be fitted with temporary replacements. Dylan Sprouse's tooth fell out in the middle of a take. Near the end of the movie, just after entering Hooters for his birthday, Sonny makes a reference to Julian about dealing with a missing tooth (at around 1h 25 mins) while holding Julian, "Hey, You! Still missin' that tooth?").