Eels, eel skin rigs or jigs trolled on wire line along the face of the rip. When I used to do it at Cuttyhunk, we'd troll through the rip to get the cows. Frequently standing 15' waves, enough to lose the boat in. Somehow it seemed the bigger the rip, the bigger the fish.
While I wouldn't be in a hurry to fish it again at night, I know that was one of the best times.
I'd try also try livelining a pogie or scup on the wire line to get it down and fish it during the day along the face of the rip. If you can troll INTO the rip or turn stern too, allowing the baits to drop back in the rip, so much the better. The big fish you are seeing have probably come up after a bait, they'll be hanging in the calm water just over the edge.
Keep at it (like I need to offer you that advice!) and you'll soon have another monster story. Probably a few.