Visible crew/equipment: In the scene where Sulu flies the helicopter and accidentally turns on the windshield wiper, look closely at the bottom of the wiper and you can see the crewman's finger manually moving the wiper.

Continuity: Notice the candle on the table in the Italian restaurant scene during Capt. Kirk and Dr. Gillian dialog. It changes height depending who is talking.

Other: When Kirk uses his hand phaser to melt the lock on the door in the hospital operating room, the phaser is not pointed directly at the lock. The beam leaves the phaser at an angle, which is probably not how the phaser would have been designed to operate.

Continuity: In the second last scene when the bird of prey crash lands under the Golden Gate bridge, Kirk orders Spock to blow the hatch so the crew can escape. The camera is pointing up inside the ship to the outside of the ship and you can see the top of an industrial shed

Continuity: The old blue Chevy pick-up that the whale biologist drives changes year models in different scenes. You can tell this by paying attention to the grille.

Factual error: The humpback whales are about to be returned to Alaska for release back into the wild. Dr. Gillian Taylor tells Kirk and Spock that Gracie is "very pregnant." In that event, the whales should be released in Hawaii instead of Alaska. Humpbacks give birth in warm, south Pacific waters during the winter and later migrate north for summer.

Continuity: In the operating room, when Kirk uses a phaser to melt the lock, the hand he is holding the phaser in switches hands in the closeup shot. Additionally, the arm holding the weapon in the closeup is no longer in hospital scrubs, but a similarly colored sweatshirt.

Revealing: When the Bounty takes off from Vulcan and flies away, no shadow is visible despite the fact that it is a very sunny day.

Factual error: When Chekov and Uhura first see USS Enterprise and then later beam aboard, the carrier shown is not USS Enterprise (a nuclear aircraft carrier), but rather USS Ranger (a conventional or oil-fired carrier). The most obvious clue is the "island", the huge structure that sits on the deck of the carrier. USS Enterprise has the most distinctive and unique island of all the USN carriers, being totally cube-like in appearance. The carrier in Star Trek IV has a more conventional style island. [It is true that the USS Ranger was used in lieu of the USS Enterprise for the movie. This is because the Enterprise was on deployment at the time. However, the give-away is NOT the shape of the superstructure on the island. By the time the movie was made, the Enterprise had its distinctive pagoda-like island totally rebuilt by Puget Sound Naval Shipyard in 1980 to a more conventional looking box structure.]

Factual error: They are about to perform major brain surgery on Chekov, but he is not nearly prepped for such a procedure. His head is not shaved, the area is not marked or masked and it has not been swabbed with Betadine.

Visible crew/equipment: When the crew starts to evacuate the Bird of Prey from the ship's hatch, the sound stage wall is easily visible.

Visible crew/equipment: In the scene where Mr. Chekhov is being interrogated on the USS Enterprise (the aircraft carrier) after being caught on board, a studio microphone being used for the shot is visible hanging above him.

Continuity: When the 'Bounty' materializes right above the whaling ship, it casts it into shadow. But the close-ups of the captain and navigator as they frantically turn the ship around reveal no trace of a deeper shadow on their faces and the surrounding waters; the lighting remains the same as in the scenes when they try to catch the whales.

Factual error: Scotty is listed in the credits as Captain Montgomery Scott. At the end when the camera pans the crew just before their pardon, Scotty wears the rank pin of a Commander (the same one worn by Commander Sulu, Commander Chekhov, and Commander Uhura).

Other: When Kirk sells his reading glasses, which are deemed antique in 1986, we see a close-up of them that shows that one of the lenses is cracked (which happened in Star Trek II). The close-up also reaveals that the stems are made of plastic. Antique plastic?

Continuity: In the scene where Kirk and Spock are walking down the street after Spock has been in the tank with the whales it is clear that it is a windy day. Both of them have their hair blowing in the wind and yet as they are offered a ride in the truck and the shot leaves them for a moment their hair is suddenly fixed again.

Continuity: Immediately after the whales' transponders are located in the Bering Sea, Gillian can be seen mouthing, "How did you do that?" without sound, then she is immediately seen and heard giving the same line from another camera angle.

Other: There is a scene were Kirk and Spock are walking along a road that in order for them to get there, they have to back track. It's the road that leads to Fort Maison - you have to go there to understand why it is a mistake.