The Little Mermaid is the last Disney feature film to use the traditional hand-painted cel method of animation. Disney's next film, "
The Rescuers Down Under", used a digital method of coloring and combining scanned drawings -- CAPS (Computer Animation Production System), which eliminated the need for cels. A CAPS prototype was used experimentally on a few scenes in
Mermaid, including the final wedding scene. Other
CGI includes some of the wrecked ships in the final battle, a staircase behind a shot of Ariel in Eric's castle, and the carriage Eric and Ariel are riding in when she bounces it over a ravine. (Notice that the wheels aren't moving when it comes down for a landing.)