What is the difference between net tonnage and gross tonnage?

Net tonnage represents the cargo-carrying capacity of a vessel and is calculated by taking the gross tonnage and subtracting certain spaces that are not used for carrying cargo. These deductions include areas such as the engine room, crew accommodations, and other spaces that do not directly contribute to the vessel's ability to carry cargo. This distinction is important as it helps in assessing the vessel's revenue-generating potential by focusing specifically on the space available for goods rather than the total volume of the ship.

In contrast, gross tonnage incorporates the entire internal volume of the vessel, including both cargo spaces and other areas that do not necessarily count towards cargo capacity. Thus, while gross tonnage gives a broad overview of the vessel size, net tonnage provides more practical information relating to the vessel's functionality and usability for transporting goods.