Dory Propeller is a type of boat propulsion system that uses an OAR (3 letters) to move the boat through the water. It is a traditional method of propulsion that has been used for centuries and is still used today. The OAR is attached to the boat and is used to push against the water, creating a forward motion. Dory Propeller is a great choice for those looking for a low-cost, low-maintenance way to power their boat.