In a container with a lid, place cleaned shrimp & remaining marinade ingredients. Allow to marinate for at least 30 minutes.
Cook rice in chicken broth until tender.
Slice zucchinis in half lengthwise; scoop out centers, leaving 1/8-inch thick shells. Place in a 9 x 13-inch baking dish.
Chop zucchini flesh that was scooped out of centers. In a large skillet, melt butter; add chopped zucchini & sauté until tender crisp. Remove from heat & add cooked rice, garlic powder & some of the parmesan.
Preheat oven to 400 F.
Fill hollowed shells with rice mixture. Drain shrimp & place on top of rice mixture. Drizzle marinade over top of shrimp boats. Sprinkle with remaining parmesan.
Bake 20-25 minutes or until shrimp is cooked & zucchini is tender crisp.