Preheat oven to 375 degrees. Wash ducks, and dry thoroughly. Tuck wing tips under back. Place on rack in low-sided roasting pan. Prick skin on thighs with fork. Pour soy sauce over ducks. Pour water in pan (do not pour water over ducks). Roast 1 1/2 to 2 hours. Split ducks in half, arrange on heated platter, and top with sauce (below). Sauce: In small saucepan, combine preserves and liqueur. Simmer 10 minutes. For variations of this sauce, add 1 cup raisins, 1 cup chopped and pitted dates, or 1 cup canned mandarin orange sections, well drained.