Editing Ebirah, Horror of the Deep (section)

==Production==
===Writing===
By 1966, Toho had their sights set on bringing back King Kong back to the silver screen. Their deal with [[RKO]] allowed them the use of King Kong for five years, an agreement that would be over in 1967. Why Toho waited so long to produce another Kong film is unknown. The planned movie, ''Operation Robinson Crusoe: King Kong vs. Ebirah'' (ロビンソン·クルーソー作戦 キングコング対エビラ ''Robinson Kurūsō Sakusen: Kingu Kongu tai Ebira''), was to be a co-production with [[Rankin/Bass]], who was about to debut their animated program, ''The King Kong Show'', in September of that same year. According to Toho Special Effects Movies Complete Works, Jun Fukuda was approached about an untitled US–Japanese ''King Kong'' co-production on April 21, 1966. Even before that, in February 1966, Toho's senior staff member Makoto Fujimoto met with a movie theater owner in Kansai and revealed that the New Year's season would see the release of a new ''King Kong'' movie.

The concept was first pitched by Shinichi Sekizawa on July 13, 1966. However, Rankin-Bass was displeased that Toho was dead-set on Jun Fukuda directing the live-action and Eiji Tsuburaya's protege, Sadamasa Arikawa, directing special effects. Rankin-Bass was equally dead set on the creative team being Ishiro Honda and Eiji Tsuburaya. When Toho refused to budge and was unable to compromise, Rankin-Bass dropped out of the project. Toho liked the script so much that they decided to simply substitute Godzilla in place of Kong and release it as ''Godzilla, Ebirah, Mothra: Big Duel in the South Seas'' for their New Year's blockbuster. Rankin-Bass and Toho would settle their differences the next year and would begin work on ''King Kong Escapes'' (1967), which was based on the recent King Kong cartoon and would feature Honda at the director's helm.

Even with the loss of one of the title characters, though, Toho continued with production on Sekizawa's screenplay. Little was done to tweak the script and Godzilla displays a Kong-inspired interest in Daiyo. It's even possible the electric shock to revive Kong was a nod to the ape's love of electricity in ''King Kong vs. Godzilla''.

According to [[Teruyoshi Nakano]], Godzilla was supposed to fight a giant octopus in this film. However, Nakano likely confused this film with an early version of ''All Monsters Attack'' (1969). Both Nakano and Fukuda acted as though they were unaware the film ever started out starring King Kong. Fukuda said, "Godzilla was in the first draft of the script that I saw. I don't know what the earlier drafts were like." Fukuda further elaborated that making the film "was like pouring two cups of water into one. I had to cut one sequence after another." What these cut scenes contained are unknown, but Godzilla's infamous helicopter spin of Ebirah, which exists only in publicity photos, was apparently planned for the film, as storyboards exist of the scene.

===Filming===
This is the first of two ''Godzilla'' films in which a Pacific island is the primary setting, rather than a location inside Japan. The second and final one is ''[[Son of Godzilla]]'' (1967).{{citation needed|date=March 2018}}

Director [[Jun Fukuda]] notes that producer Tomoyuki Tanaka was not particularly active on this production, with the exception of being involved with the budget. The producer would, however, visit the set "often" to watch progress but only as an observer.

Daiyo was originally to be played by [[Noriko Takahashi]], from ''[[Frankenstein vs. Baragon]]'' (1965), but fell ill with appendicitis during production was replaced with [[Kumi Mizuno]] at the last second.<ref>{{cite book|title=Toho Tokusatsu Actress Complete Works|date=2014|publisher=Yosensha|page=109|isbn=978-4800304957|language=Japanese}}</ref>

Although [[Eiji Tsuburaya]] is credited as the special effects director, actual directorial duties were handed over to [[Teisho Arikawa]], who at this stage had been promoted to Tsuburaya's first assistant director. Tsuburaya still had the final say on effects sequences but served more of a supervisor role on the production.

With a new special effects director in the seat, Toho tried to limit the effects budget. Sadamasa Arikawa lamented that Toho likely did this due to his inexperience and TV history, noting that "Toho couldn't have made too many demands about the budget if Mr. Tsuburaya had been in charge" and that he "was also doing TV work then, so they must have figured I could produce the movie cheaply." To keep the budget down, Toho instructed Arikawa to avoid expensive composite shots as much as possible. Although the movie has minimal composite shots, it is not devoid of them as scenes such as Godzilla's foot composited near actress Kumi Mizuno or a sequence of Mothra composited as her followers rush toward her are some examples of these sequences that made it into the final film.

Jun Fukuda was not fond of the film. In an interview, he was quoted saying, "Toho sent me a copy of the VHS tape edition of Godzilla vs The Sea Monsters when it was released. It was like opening up an old wound, I didn't watch the tape."

===Music===
Director Jun Fukuda selected Masaru Sato to score his films to give it a "different touch from Ishiro Honda's", noting Sato's music was lighter than Akira Ifukube's. Producer Tomoyuki Tanaka didn't agree with this decision but Fukuda won out in the end.

===Special effects===
The underwater sequences were filmed on an indoor soundstage where the Godzilla and Ebirah suits were filmed through the glass of a water-filled aquarium, with some scenes of the Godzilla suit shot separately underwater as well. Haruo Nakajima wore a wet suit under the Godzilla suit for every scene that required him to be in the water, which took a week to complete the water scenes, Nakajima stated, "I worked overtime until about eight o'clock every day. I lived in the water! Generally, in the summer, everybody wants to go in the pool and play, but, when it comes to kaiju movies, it is totally different. Most of the scenes that they shoot in the water are not in the summer, but in the winter. In the middle of winter, shooting started at nine in the morning, going until noon, and then we'd take an hour off. But we'd go from 1:00 P.M. until around 5:00 at night. I needed to stay in the water all day in the suit, and shooting took a week."{{citation needed|date=April 2022}}

The Side Monsters that featured in this film were largely dictated by suits and props that were still available from previous films. For example, the [[Mothra]] was the same prop seen in [[Ghidorah, the Three-Headed Monster]] and the giant condor was a repurposed Rodan prop used in flying scenes. Other places where the low budget of the movie can be seen is in the island setting which was picked, as islands are much cheaper to make miniatures of compared to cities. This island trend carries on in other movies such as [[Son of Godzilla]].