Cody,
It seems that I am the wet blanket, but I think you are rushing it. I appreciate your enthusiasm, but you are asking questions about how to attach a float line to a pole spear so a big fish won't take it away from you, and as far as I can tell you haven't shot a small fish.
You have questions all over the board, but have you been diving yet? If not, just get in the water and try it out. Before then, I don't think you will know what questions to ask or be able to really appreciate the answers.
Regarding this particular one- I really don't think there is much of a relationship between your static time on the couch and your bottom time spearfishing, and if you are a spearfisherman, its the latter that counts, or at least counts a bit.
I know what my bottom times are spearfishing. They are not very impressive, but I have no idea at all what my static time out of the water is, because I never hold my breath out of the water. It makes me feel breathless, and I don't like that.
But in spite of never holding my breath out of water, I shot that 62 pound fish in my avatar at age 69 a few weeks ago. My ignorance must not be significant.
Would you like to spear a fish like that? If so, go spearfishing some time soon. After a bit of experience, then come back and ask questions.