Score the surface of the ham, making diamond shapes about 1cm deep. Place the ham in a large, resealable bag. Add the bourbon, brown sugar, crushed pineapple, honey and garlic to the bag; refrigerate at least 8 hours, turning the bag over several times while marinating.
Preheat oven to 180 degrees C.
Transfer the ham and marinade to a large baking dish; pour the water into the dish. Attach the pineapple rings around the surface of the ham with toothpicks.
Bake in preheated oven until the internal temperature reaches 95 degrees C, basting occasionally with the sauce in the pan, 90 to 105 minutes.