Continuity mistake: As the Dynamic Duo near the buoy, Robin is seen for a moment wearing headphones, when the rest of the time in the Batboat, he's not wearing them.
Continuity mistake: When the Batboat first takes off, the flashing red emergency light is on. In the close-ups, it is off.
Continuity mistake: At the airport, the Batcopter is ready to fly. As it ascends, look at the front of the bottom side. The only thing there is a standard search light. Later, when over the yacht, Batman drops the Bat-ladder, which appears to be attached to the bottom front next to the light, but wasn't there on take-off. The class of chopper used didn't have room for a hidden compartment.
Continuity mistake: In the beginning, after Batman and Robin are in the Batcopter, in a close-up shot, you see Robin with the Bat-camera next to him, when there wasn't anything in the cockpit with them when they took off. After he raises it to get a reading and take pictures, a wide angle shot shows them in the chopper with no camera, and then another close-up, and the camera's back.
Continuity mistake: When Batman and Robin are circling in the Batboat over the submarine with Robin shooting at it inside the circle, the boat is shown circling in the same tight circle while underwater shots of the submarine show it moving forward under the water. The sub's position would have been changing so the Batboat would have had to change position with it.
Answer: The timeline of the movie is important to consider. The 1966 film began production while season 1 of the TV series was being aired. Eartha Kitt didn't play Catwoman until season 3. According to the TV show "Biography", Newmar was suffering from a back injury and unable to reprise her role for the movie. But she was able to recover by the time they started shooting the 2nd season. So, for the movie they hired Meriweather.
Bishop73