Faldage wrote about "listing": >Unbalanced cargo could cause the same condition.<

True. A shift in cargo or other factors could cause a vessel to list. Many of the clammers (clam boats) in this area have that problem because of the regulations...they are only allowed to go out at certain times and tend to overload...so many of them go down when the clam-cargo shifts in the hold (not to say that a boat HAS to go down when the cargo shifts, guys!) But, actually, I've lost a few friends that way. I just thought the image of a foundering or sinking ship was the classic example of the word list or listing. I see, now, that literalism is part of the fun of the wordplay here...I'll make a note of that.

And all this semantical dissection of "listing" brought this to mind, so here it is:

Can a submarine sink if it's already submerged? Or at the bottom? Do we need a new word? Or do we need to say "losing air," "lost air," or "lost all air" instead?