Hi all,
Excelent Replies regarding drag pressure, however im not sure if it is the best idea to apply massive amounts of drag to fish who are likely to go for reef or any type of structure (unless you have the gear to skull drag it). in my experiences with large Snapper, Jewfish and Kings is to put the reel into freespool when you believe they are aproaching the bottom/ pylon.
the more pressure, the more pain for the fish, the more likely to bust you up.
freespool until you get some angle on the line and slowly re-apply pressure, this way you tire the fish out rather than freak it out!
good luck