Tell me, Brave Captain, why are the wicked so strong?

Perhaps the world was a more literate place when "Seven Waves"/"Abandon Ship" was made.

During the storm, one of the survivors in the water says, loudly, "Now is the time of the Spartans!" Unless this is a quotation, it is a pretty random remark, and if it is a quotation, it isn't one that would be likely to register with any group of shipwreck survivors in 2008. (You would be better off shouting "I am the King of the World," but, like, really ironically).

Throughout the movie, the Posh Spice woman played by Moira Lister continually calls Tyrone Power's character, "Brave Captain" in an arch way.

So, the first thing I wonder is: whether there was, current in early 1950s culture, a well-known line of poetry, or maybe a well-known phrase from a fairy story or folktale, that mentions "Brave Captain," and which she is referencing?

Secondly, at one point in the movie, soon after it reached its central moral dilema, Posh Spice delivers one of her "Brave Captain" disses, and either she or another character remarks, "Brave Captain, why are the wicked so strong?"

Again, there is something about the way the line is said that makes me think it might be a quotation, then familiar to movie-going audiences, but not so familiar now ... except to Tom Waits' fans.

For them the line would be familiar from the song, Mr Siegel from Waits' 1980 album Heartattack & Vine. The song in question is told from the point of view of a doomed gangster on his adventures, and the chorus of the song goes:

You've got to tell me, Brave Captain
Why are the wicked so strong?
How do the angels get to sleep
When the devil leaves his porchlight on?

Hearing (almost) the same line in "Abandoned Ship" made me wonder whether Waits had caught the movie on the late show, at around the time he was writing the song, or whether he had maybe taken the line from the same place as the movie's writer.

So, I'd be grateful for any light that anyone- in particular anyone who might have caught the film on its first release- could throw on the matter.

Just in case anyone there might know, I'll post a copy of my question on the Tom Waits board as well.