Heat a slotted broiler pan in a preheated 450 degrees F oven.
Pat scallops dry and quarter them. Combine the vinegar, sugar, garlic and ginger and marinate the scallops 10 minutes. Arrange the bacon slices in a single layer. On each half-slice of bacon, place 2 slices of water chestnuts. Top with a scallop piece and wrap with the bacon, secure with toothpick. Place scallops on sides, exposed side facing out. Draw garlic and ginger from vinegar and drizzle over scallops then bake 10 minutes, turning once.