Cut the legs off, and chop half of the calamari into ½” rings, half into triangle shapes--scoring these with a crosshatch.
Soak in buttermilk for 10 minutes, up to 8 hours.
Meanwhile, heat canola oil to 400 degrees F.
Whisk together flour, cornmeal, salt, and paprika.
Drain calamari and toss in flour mixture.
Fry in hot oil in small batches to avoid crowding the pan.
Pull once golden and crispy, a minute or so, and transfer to a baking sheet.
Season with sea salt and place in low oven to keep warm.
Continue frying calamari in batches.