Wipe ducks dry inside and out, season with salt and pepper, and place in roasting pan close together, breast sides up. Cover with strips of bacon. Roast at 400 degrees for 25 minutes or until done to taste. Meanwhile, heat to boiling in small saucepan the orange juice, garlic, mustard, ginger and salt. Remove from heat and during the last 10 minutes of roasting, remove bacon from birds and brush them with the mixture. Mix cornstarch with 1/4 cup of the water and add to remaining orange sauce. Pour in remaining water and stir over low heat until sauce thickens. Place ducks on heated platter, slice and serve with the orange sauce.