An automatic animal watering apparatus includes a dish having an automatic watering valve disposed therein. When the valve is first closed, a water level in the dish is at a maximum level, and a hydraulic source pressure acts only across a smaller cross-sectional area of a valve seat which is closed by the valve, thus requiring only a first lower buoyancy force acting on a valve actuator float to maintain the valve closed. The water level can then drop from the maximum water level to a minimum water level before the hydraulic force action on the valve overcomes the first lower buoyancy force on the actuator float and reopens the valve. Then when the valve opens, the hydraulic source pressure acts against a larger cross-sectional area of the valve, thus requiring the buoyancy forces acting on the float to rise to a second higher buoyancy force to reclose the valve. The automatic watering device may be mounted on an external structure through the use of a mounting bracket, and removable mounting pins may connect the dish, the mounting bracket and a cover plate of the dish.