The term 'Boats' Backs' refers to the back end of a boat, which is also known as the stern. The stern is the part of the boat that is located at the rear and is usually the widest part of the boat. It is often used as a platform for activities such as fishing or swimming. The term 'Boats' Backs' is often used to refer to the stern of a boat, as it is the part of the boat that is most visible from the back.