Cut each slice of bacon in half. Wrap one water chestnut in 1of the pieces of bacon, making sure to overlap. Secure the bacon with a toothpick and put it on a sheet pan. Repeat the process with the remaining water chestnuts, pineapple chunks and scallops.
Put the pan into the preheated oven and bake until the bacon is crisp, about 20 minutes. Remove, let cool 10 minutes and serve immediately.