Origin of nautical "Pig" superstition

Factual Questions
1

This is a three-parter:

(1) I’ve heard submariners say “let’s kick this pig” to mean “let’s get this (event, caravan, thing) moving.” I had always assumed that this was related to the naval slang “pig boat” for submarine. So, why are submarines called pig boats?

(2) I found several plausible explanations to the above question, but no sources. I’m not surprised; the military love to go back and make up wild pseudo-historical tales when they don’t understand the origin of something. Anyhow, while searching for the answer to the above, I discovered the widespread superstition that it is apparently bad luck to say “pig” onboard a boat. Why?

(3) And of course, the third part, tying it all together: are these two porcine naval traditions connected in any way?

Like I said, I googled this one to death; what I’m hoping for are some good sources (although I admit that putting it in writing doesn’t necessarily make it authoritative). “My dad was in the Navy and he said” is probably going to get me yet another disparate answer to add to my collection.

Thanks in advance for anything you can dig up.
Oink Oink,
Jurph

2

I located a research paper which offers the theory that pigs were considered to be associated with the Devil from Old Testament times, and therefore bad luck on ships.

This cached page offers the theory on “pig boats”:

3

Your first line was pretty accurate. To “kick the pig” is to raise anchor and proceed. The “pig” bit refers to the fact that the old anchors were usually cast iron (pig iron).