Hey, didn't you get broken off by some mystery fish in King Harbor on the fastrac??? Maybe it WAS a thresher. I've actually been getting into thresher fishing lately. We plan on doing some sharkin this summer from the skiff. A lot of threshers are caught incidentally around here while salmon trolling. I'd suggest finding a big ball of bait and trolling a bait-o-matic, or rapala through it. Sounds like your dad had the right gear afterall... Use heavy line for sure. Those incidentals while salmon fishing pretty much always spool the salmon gear. I'd say 40# minimum. Hey, give the fastrac a try too, you never know. That 5" one might do the trick. Put those VMC hooks on it first though.
-Brian