AFAIK it is an enormously-long wire that is extended out of the submarine. I am not familiar with the logistics of doing this (e.g. unspooling it using the sub'

AFAIK it is an enormously-long wire that is extended out of the submarine. I am not familiar with the logistics of doing this (e.g. unspooling it using the sub's momentum through water or motorized extension, or if the antenna is extended vertically or horizontally). I have a Navy friend that was a squid and this is his information. It could be totally different these days, as my buddy was on subs in the first part of the last decade.