The term 'shell accessory' can be summarized as an OAR, which is a three-letter word. An OAR is a long pole with a flat blade at one end, used to row or steer a boat. It is also used to propel a boat through the water by pushing against the water. Oars are typically made of wood, but can also be made of metal or plastic. They are often used in pairs, with one person rowing on each side of the boat.