Marinate the water chestnuts in soy sauce for 1 hour. Drain. Roll each chestnut in the brown sugar. Wrap each chestnut with a piece of bacon. Secure with a toothpick. Arrange on a cake rack in a shallow baking pan. Bake at 400 degrees F for about 30 minutes or until golden brown. Drain on paper towels. NOTE: This can be prepared ahead of time and stored in refrigerator until ready to bake.