In a medium bowl, mix together teriyaki sauce, garlic and ginger root. Place chicken livers and water chestnuts in the mixture. Marinate in the refrigerator at least 2 hours.
Heat oil in a large, heavy saucepan to 375 degrees F (190 degrees C).
Wrap each half slice of bacon around one chicken liver half and a slice of water chestnut. Secure by skewering with small skewers or toothpicks.
Carefully lower skewered wraps into the hot oil in small batches. Deep fry 3 to 4 minutes, or until bacon is evenly brown and of desired crispness. Remove from heat and drain on paper towels.