A similar situation happened to me about 20 years ago at Westport while out on a charter boat for salmon around this same time of year. We weren’t having much luck for salmon so the skipper took us further out and put us over a small reef for some bottomfish. That’s where the “beast” hit. After working the fish for a bit, it just stopped and held it's ground at mid depth. No screaming runs, head shakes, twists or twirls; just a steady throbbing pull as it took us further and further off shore with the tide. As it became clear it would be a long protracted battle, the skipper proclaimed it to be a large "skate", suggested I break it off immediately and headed back to the bridge. I was in shock and in utter disbelief as he fired up the engines and headed back for the reef with me still attached to the leviathan that would not break off. With the line just peeling off the reel all I could do was hold on with all I had. For a moment I thought for sure I was going to lose my rod right along with the fish, but fortunately I did break off at the leader before I was spooled. At the time I was pretty torqued at the skipper. I later got over that, but today I still wonder what the heck I had on down there that day. I guess there are some things we’ll never know.