A boat is a watercraft designed to float on, and provide transport over, water. Usually this water will be inland or in protected coastal areas. However, boats such as the whaleboat were historically designed to be operated from a ship in an offshore environment. In Naval terms, a boat is something small enough to be carried aboard another vessel (a ship). Boats that are notable exceptions to this concept due to their large size are the Great Lakes freighter, riverboat, and ferryboat. These examples do, however, generally operate on inland and protected coastal waters. Modern submarines may also be referred to as boats (in spite of underwater capabilities and size), but this is possibly due to the fact that the first submarines could be carried by a ship and were certainly not capable of making offshore passages on their own. Boats may have military, other government, research, or commercial usage; but a vessel, regardless of size, that is in private, non-commercial usage is almost certainly a boat.