When the submarine is in San Diego it is broad daylight. Someone says that the time in Melbourne is 15:00. (3 PM). Since San Diego time is either five or seven hours later (depending on the time of year and allowing for daylight saving), it should already be dark in San Diego.
When Hosgood announces Holmes to the Admiral, she calls him Lieutenant Holmes using the American pronunciation, instead of the Australian "Leftenant". Curiously though, navies of the British tradition actually pronounce the rank a "L'tenant" but this subtlety is usually overlooked in Hollywood for the more exotic "Leftenant" which is actually the army pronunciation.
Despite having a nuclear physicist aboard, the man going ashore at San Diego does not have his gloves or the cuffs of his anti-radiation suit sealed with tape. He also goes ashore and finds the transmitter key in the large refinery in under three-quarters of an hour, without carrying any portable radio direction finding equipment (unless that silly loop on his head is supposed to be it). Plus, the radio direction finder would only point to the transmitting antenna, not the telegraphy key itself.
When the source of the Morse code is found, the finder sends back a message
in Morse code: "Coke bottle on key ~ held by window shade." But back in the sub, the captain rips the paper message from the typewriter before the message is finished and before he knew about the shade and he states: "Window shade tugging on a Coke bottle."
Mary points out to Peter that if he needs to get into Melbourne by 11:00 for his appointment with Admiral Bridie, he'd better hurry. By the clock on Admiral Bridie's office wall, Peter clearly arrives for his 11:00 appointment at 10:05.
Party for Dwight in Frankston. Mary returns to the room with a plate of snacks. Being upset by the discussion about the war, in the close up she is focused on something to the left of her. The following wide shot of the room is presenting her in an attitude towards the middle to right side of her position. Her hair seems to be flatter or even moister.
Phillip Island Grand Prix. The crash of car no. 31 (Roadster). He spins sidewards, the front wheels clearly point to the left. The set-up for the stunt crash presents the car with front wheels pointing to the right, the driver (dummy) slumped to the left, while the left side is already on fire. Possibly a cable to trigger an explosive device is covered over with a very dark, therefore clearly visible, strip of asphalt.
As has been pointed out in another "Goof", Peter's appointment with Admiral Bridie is for 11:00, yet when he enters Bridie's office the clock on the wall reads 10:04. In addition to this error, throughout Peter's meeting with the Admiral, followed by the Admiral's subsequent exchange with Osgood, the time on the clock never changes from 10:04, though several minutes have elapsed.
Near the end of film when Moira is watching the Sawfish leaving Port Phillip Bay, it's evident in the wide shot that the sail of the Sawfish is clear. However, in the tight shot of the sail before that, while other crew are clearing the sail, Waters is still on the sail, then after the close-up of Moira, Waters is shown in close-up still atop the sail.
Near the end of the film when Moira is watching the Sawfish leaving Port Phillip Bay, the speed of the boat in the tight shots from the top of the sail doesn't correlate with the speed of the boat in the wide shot, seen from Moira's perspective from ashore.
Two race cars crash off to the left of the race course. However, when the smoke is shown immediately afterward from a shot looking at Julian in his race car and behind him, the smoke is on the other side of the course.
When seeing the views of San Francisco through the periscope, we see a view straight at the Ferry Building and a few seconds later a view directly up Laguna St (past the long gone large natural gas storage tank). These views can't be seen from the same place. The sub would have had to move at least three miles during the few seconds between the views.
The 'Australian Grand Prix' race is supposedly held on Phillip Island in Westernport Bay, Victoria. Being a small island, the beach is visible from many parts of the track, but is not in the film. Also, the surrounding area of Westernport Bay is not mountainous as depicted, only slightly hilly. The real track was probably located in the US, for filming convenience.
The race footage was from Riverside, the now closed track east of Los Angeles. The site is now a housing development and shopping center.
In the initial scenes in the film, Gregory Peck gives the order: "Open Main Induction". The sub is supposed to be atomic powered. Such subs do not have induction valves because it is the air intake for a conventional engine. Reactors do not require an air intake.
When the Sawfish departs on its final voyage, the safety handlines and stanchions are still in place. They would have been removed as part of the rig-for-sea procedure, if for no other reason than they could break loose and foul the stern planes, rudder or props.
When the crew member discovers the Coke bottle on the Morse key, on the bench by the windowsill is a book entitled "Valve Data Manual". In San Diego, in 1964, it would have been a "Tube Data Manual", "valve" being the word used for tubes in the UK and Australia (and likely other parts of the Commomwealth).
Before the submarine's deployment on its proposed 13,000 mile round trip, Dwight is asked if he has enough power on-board his nuclear sub. A nuclear sub's range is only limited by the amount of food it can carry and the endurance of the crew. The time between refueling a nuclear sub is measured in years if not decades. Plus, the sub could easily cover the 13,000 miles in three weeks or less.
Gregory Peck's character refers repeatedly to the Australian Government science body as the CSIR but the organization is called the CSIRO - the Commonwealth Scientific and Industrial Research Organization.
When the Sawfish is in San Francisco, the periscope camera focuses in on the Ferry Building, showing 'Port of San Francisco' and clock. The clock says approx 8:10 am. That it is morning is true because the sun is shining on the ferry building and clock - both face east. However Capt. Dwight Towers says that it will be dark in an hour. That cannot be true if it is 8 am.
This is not a goof because 8:10 is not the current time, but the time when the clock lost power after the war.
At the very beginning of the film, a radio announcer is heard reporting that no life survives anywhere but Australia. Later Admiral Bridie suggests that it might be possible for life to continue in Antarctica, indicating that that continent is also not yet affected by radiation. In any event, the basic premise - that Australia would still harbor life while every other site on the globe has been destroyed or rendered lifeless - including, among other places, New Zealand, farther south and much less of a target than Australia would be - is illogical and physically a virtual impossibility. (By contrast, in the novel the entire Southern Hemisphere is untouched by the atomic war itself, though the radioactivity gradually drifts southward.)
The time line in the film concerning the shortage of oil is contradictory and makes no sense. The Melbourne street scene near the beginning shows an apparently long-abandoned car, with everyone else riding horses or horse-drawn vehicles, bicycles or the electric tram - a scene that only makes sense had the oil shortage been of long-standing, since most people could not obtain horses so quickly. But according to the radio report heard a short time earlier the atomic war had just ended, so there should still be much normal traffic on the roads before oil and gasoline supplies disappeared. On the other hand, as Peter enters the Naval building Admiral Bridie is telling Osgood that he has just seen the report stating that all oil comes from the Northern Hemisphere. It makes no sense that Bridie would only then be reading such a report if oil had by then become so unavailable that all automobile traffic had already ceased.
At the Holmes' party, Dwight asks Moira about Julian, saying, "I take it that he's English and that he's here on some kind of scientific job", and later on, during the sub's cruise, Julian tells Peter he'd been in San Francisco "once on the way down", presumably from England. All this makes it appear that Julian has not been in Australia long and had not intended to stay before the war broke out. But why then does he appear to be friends of long standing with so many people (such as the party guests), not to mention his having had an apparently long-ended love affair with Moira?
When the film begins, it is, according to the calendar on the Holmes's wall, January 1964, and later that day, when Peter asks Admiral Bridie how long they have until the radiation arrives in Melbourne, the Admiral replies "about five months" - which would mean sometime in June. Yet later, when Julian tells Moira he's going to enter the auto race, he says it'll be held on "the 6th of August" - by which time, according to what was said at the start of the film , they would have all been dead for two months.
The periscope views of San Francisco show several sea gulls flying overhead when presumably all life is gone, and inadvertently shows a police squad car blocking a side road with its flashers on undoubtedly to keep side street traffic off the main street in the shot. In a close-up periscope view now only the top of the car can be seen, the flashers out of view behind the rise in the intervening hill.
Lt Sunderstrom enters the oil refinery and walks past a sign warning away trespassers. Although the setting was supposed to be San Diego, the warning sign uses the British/Australian spelling of the word "AUTHORISED" rather than the American spelling "AUTHORIZED", which gives away that an Australian refinery stood in for an American one.
In the very last shot of Dwight, upon the bridge of his submarine just before he disappears below, it is clear the sub is not moving under power but is instead just drifting in the bay, as no wake is visible and the vessel is making no forward movement.
The goof items below may give away important plot points.
If the radio signals coming from San Diego had "started the day before yesterday", as Admiral Bridie tells Commander Towers, what had caused the Coke bottle - later discovered tugging on the window shade and resting atop the Morse key, hitting it and sending out random signals - to suddenly tip over and get caught in the window shade's pull string? The set-up is so improbable that it could only have occurred by a human hand, which would have meant that the signals should have been being transmitted for months, since the end of the war - not merely for only two days.