The term 'BACKS AT SEA' can be solved by the crossword solution 'STERNs' which is a six letter word. The term 'STERNs' refers to the back of a ship, which is an important part of a vessel's structure. It is the part of the ship that is located at the rear and is usually the highest point of the ship. The term 'BACKS AT SEA' is often used to refer to the sterns of ships, as they are the most visible part of the ship when it is out at sea.