In a glass bowl, toss shrimp with teriyaki sauce. Cover with plastic wrap and let marinate in the refrigerator for one hour.
Adjust oven rack to the middle setting and set oven to preheat.
Remove shrimp from marinade and place each on a half strip of bacon with a water chestnut. Roll and secure with a toothpick, then place onto a broiler pan approximately 1/2 inch apart from each other. Discard remaining marinade.
Broil ramakis for 5 minutes on each side, or until the shrimp is pink and the bacon is cooked (keep the oven door ajar and watch carefully). Drain on paper towels and serve immediately.