There is a pinnacle off Makah Bay sticking up out of an area of sandy flat bottom that was loaded with big yellow eye rockfish and lingcod that would dive into holes as soon as they were hooked. It felt like a fish on and then a solid unmovable pull, as the tide moved you off the spot, until breaking off. The trick was to not give an inch of line on the hookup to pull them out of there. I don't really think this is what is happening from the description because of the high speed of the chase and the turns .
I have seen a 527 lb halibut hanging on the scale at Bay Fish ,1973 or there about, and can imagine that size of halibut could be quit a battle on sports gear.