Bring a large pot of lightly salted water to a boil. Add shrimp, and cook for about 5 minutes, until pink. Drain and set aside.
Place the onion and green pepper in a large bowl. Add vegetable oil, ketchup, cider vinegar, sugar, mustard, and capers. Season with garlic powder, Worcestershire sauce, salt, pepper and hot sauce, and mix until well blended. Place shrimp into the bowl with the sauce, cover, and refrigerate until thoroughly chilled. Serve cold.
