SuPrBuGmAn
Contributor
Good questions... I carry three spools in caves too as that's as many jumps as I am allowed to do. I carry them on my butt plate (D-Ring).
Carry more spools than jumps you'll do. It'd suck to do a lost line search after you deployed that third jump eh? At this point, lots of people recommend carrying a redundant safety, just incase you fubar the first when you need that line.