Another "vote" for a large six-gill shark.

Decades ago while salmon fishing I hooked what turned out to be a small (6 /12 foot) six gill shark of the "windmill hole" - west end of Mutiny Bay and got it to the boat at Double bluff. Took an hour to get it to the surface and 4 mile chase.

Consider that the above fish was a small six-gill. The maximum size for the species is thought to be 15 feet with a potential weight of more than 2/3 of a ton. I would think such a fish would be more than a match for any tackle commonly used in Puget Sound fisheries; especially considering it would likely be hooked in or near deep water.

Curt