In the movie (unlike the book), the submarine's crew tells the captain near the end of the movie, "We took a vote - we want to go home." So, apparently, the submarine heads back to the United States (unlike the book, where the submarine is sunk right in Australia). Do you think the sub ever made it back to the United States? There were incidences of radiation sickness already among the crew.
shareA bit earlier, Dwight tells Julian in the garage that they are returning home--
Julian ask how long and when Dwight says a day, maybe two, Julian says "you might not have that much time..."
I always took that to mean that the radiation had arrived in Melborne-- Julian says it was 9 points in the red and rising.
So a few days exposure would make one come down with radiation sickness. However, if you could remove yourself from the exposure soon enough, you might be ok and not get sick right away-- or perhaps not at all.
So the sooner Dwight and the crew were on the sub, underwater, and breathing filtered air made from sea water, the better.
Melborne to the East Coast of the U.S. via the Horn (assumes passage through the Panama Canal untenable) would be something like 15,000 sea miles. At say 20 knots average speed (and that's a rough guess) per hour, it would take about 1 month to get home to New London, CT.
So if the crew were already seriously sick before leaving, they might not make it.
If they were basically healthy and removed themselves from further exposure, yeah, they could make it back.
Of course, once they arrived, it would pretty much be all over after about a week's exposure al la Swain.
Unless of course they could find some sort of shelter that was up and running and could sail there :)
AE36