Trivia: The aircraft carrier that Uhura and Chekov find is actually the USS Ranger, standing in for the USS Enterprise. The Enterprise was at sea during filming.
Trivia: Longtime Hollywood film composer Leonard Rosenman scored a stirring title theme for "Star Trek IV: The Voyage Home," and it was well-received as an original Star Trek theme at the time (1986). However, the Star Trek IV title theme was actually a note-for-note recycled piece from the 1978 Ralph Bakshi animated film, "The Lord of the Rings," which Leonard Rosenman also scored. The victory fanfare in the Lord of the Rings' final battle scene is virtually the same music as Star Trek IV's title theme.
Trivia: McCoy's statement "Spock, you really HAVE gone where no man has gone before!" is the first time that the TV show's title catchphrase was used in-universe. Since this movie other productions such as "Star Trek V" and "Star Trek - Enterprise" have established the phrase as Starfleet's motto.
Trivia: The scene in which Chekov and Uhura ask people on the street where Alameda is was basically unscripted. Most of the people, except a few who were hired to react, were actual pedestrians, and the policeman was hired only to be bodyguard to the actors. Leonard Nimoy only gave Walter Koenig directions to repeat "nuclear wessels" load and clear, and then sat back with the camera in a 'Candid Camera' type manner. (00:43:20)
Trivia: Eddie Murphy was originally planned to take the role of the 20th Century Terran who assists the Enterprise crew in their efforts to retrieve the Whales. He would have played an English teaching college professor who believes in extra-terrestrials and witnesses the Enterprise crew's arrival when they materialise above a football game being watched by Murphy. While everyone else believed it to be a special effect for the game, Murphy would believe it was E.T.s arriving on Earth. This plan was eventually abandoned when the studio realised that they could make more money by keeping the two franchises separate and making a Trek film and a Murphy film. In the completed film, Murphy's character was changed to a female marine biologist and played by Catherine Hicks (although many of the scenes written for Murphy's character were used, if slightly altered).
Trivia: The scene in which Chekov and Uhura beam onto the Enterprise aircraft carrier was originally slightly different. It was scripted that they would sneak onto the ship undetected, but the American Navy believed that it would be impossible for two intruders to get past a military security force. So it was re-written that the transporter had enough energy to beam the pair onto the carrier, but not to get them back off.
Trivia: The Cetacean Institute is really the Monterey Bay Aquarium in Monterey Bay, California; the Institute's logo also belongs to the Aquarium. (00:45:20 - 00:47:50)
Trivia: The medical device on Chekov's forehead is made from parts from the AMT Klingon Bird of Prey model kit.
Trivia: For the opening credits, composer Leonard Rosenmann had recorded an orchestral rendition of Alexander Courage's theme music from the original TV show, but the final film opened with its own theme instead. The original series theme is only heard sparingly throughout the films and it wouldn't be until 'Star Trek' (2009) that it would be played in full (over the end credits in that case). Rosenmann's take on the Courage theme can be heard on the 'Star Trek IV' soundtrack.
Trivia: On the original VHS and Paramount Widescreen DVD releases, the synopsis on the covers says this, "A thrilling, action packed mission for the Starship Enterprise". As anyone who knows their Star Trek, this was the one movie that didn't feature the Enterprise in any capacity except as a flashback at the start and a brief reprisal at the end, the Klingon Bird of Prey was the ship they had the adventure in.
Trivia: Outside of the US, the title was modified to 'The Voyage Home: Star Trek IV' on promotional materials as well the film itself: the opening credits briefly faded into a completely new, custom-made animated title screen, in fact. The first PAL VHS releases in 1987 carried this title, but subsequent video releases reverted to 'Star Trek IV: The Voyage Home.'.
Chosen answer: This question has been answered a number of times by various individuals, all saying pretty much the same thing. The answers have been most satisfactory given the question revolves around a fictitious situation and the answer (s) need to be accepted as complete for this purpose. Any dispute or non-acceptance should be addressed in a Star Trek forum. Any ignoring of the Prime Directive was done to save the future of Earth, as the probe would have wiped out all life on Earth. Essentially, nothing that was done in the past resulted in major changes that would make Earth 300 years later appear any different, and no major futuristic technologies were revealed. The major one, Chekov's communicator and phaser being left behind did not result in anybody learning secrets. In the film, the phaser didn't function because of the radiation. It's presumed then the radiation permanently damaged the equipment so it appeared to be nothing but a toy or prop. However, in the novel "The Eugenics Wars: The Rise and Fall of Khan Noonien Singh", Roberta Lincoln was sent by Gary Seven to recover the items from Area 51 before any secrets were learned (and as stated before, additional corrections to Earth's timeline could have been done that aren't addressed in the film.) The subsequent loss of a suspicious "ruskie" would have hardly affected the era that was already in the midst of the Cold War. McCoy even questions that giving Dr. Nichols the formula for transparent aluminum could alter history to which Scotty replies what if Dr. Nichols is the one who invents it, to which McCoy agrees (in a later novel it is reveled that Scotty already knew Dr. Nichols invented transparent aluminum, so history was not changed.) The miraculous recovery of the old lady (growing a new kidney) was done by a pill so that any examination of her would not reveal the futuristic method involved. She would be a bewilderment to the medical community at best, and most likely misdiagnosis would be to blame. And just because she got a new kidney does not mean her life would have been extended, she could have died some other way in both timelines. And as stated before, Gillian simply wasn't vital to Earth's history. She could have contributed nothing of importance to society and died alone and childless. And a missing pair of breeding Humpbacks would hardly affect the extinction of their species, however in the future, they are already extinct, so little changes would occur. As for any questions about people seeing the Klingon ship in the past, who would believe them? People have long been claiming to see spaceships and aliens to little or no avail, so why would anyone believe a handful of people who said they saw aliens in a spaceship steal 2 whales? However, as with many time travel situations in films and novels, it's possible the events of the 23rd century as they appear in the beginning of the film are a result of Kirk and company's actions in the 20th century since the events already occurred even though Kirk and company had not yet done it themselves (this is where a discussion forum on the film would be advised, or a discussion forum on the theories of time travel).
Possibly the most convoluted and poorly-reasoned series of answers I've seen on this site. So far.
Charles Austin Miller
I think they're pretty logical actually.
I think your opinion would be in the minority. There is nothing exceptionally convoluted, nor poorly reasoned in the response.