Put the salmon, 1 tablespoon water, 1 1/2 teaspoons curry powder, 1/2 teaspoon salt, and pepper to taste in a microwave-safe bowl.
Cover with plastic wrap and microwave until the fish is opaque, 2 to 3 minutes. Flake with a fork and cool slightly. Stir in 1 tablespoon tartar sauce, the cracker meal, ginger, half of the scallions and the egg. Form into 4 patties and freeze until firm, about 10 minutes.
Meanwhile, whisk the remaining 7 tablespoons tartar sauce and 1/2 teaspoon curry powder in a bowl. In a separate bowl, mix 1 tablespoon of the curried tartar sauce with the bell pepper, celery, mango, remaining scallions, lime juice, 1/4 teaspoon salt, and pepper to taste.
Heat 1/4 inch of vegetable oil in a nonstick skillet over medium heat. Sprinkle the patties with cracker meal on both sides and fry until golden, 2 to 3 minutes per side. Drain on paper towels. Serve with the mango salad and curried tartar sauce.