Free: Contests & Raffles.
They also smoke well,
Mackerel are great grilled if you eat them the day you catch them. They are oily and that gets fishy really fast. My dad and I would go deep sea fishing for Atlantic macks and catch a boatload. Clean 'em on the boat and freeze most of them. He wasn't into smoking at all. I didn't start doing that until I got out here.
The aggressive marinade probably helped a bunch. When we caught big kings in the gulf, we would steak them out and grill em hot. Not the biggest one we ever caught but a respectable King.