1. Combine the grapefruit juice and gin in a shaker. Rim each highball with salt and grapefruit zest. Pour mixture evenly into the 4 glasses.
2. In a sauté pan over high heat, add 1 tablespoons olive oil. When it starts to smoke, add the scallops. Cook until golden brown, turn, reduce the flame to medium, and baste with the reduced orange juice. When fully cooked, baste one more time and sprinkle with sea salt. Skewer and serve over the drink.