From Wikipedia, the free encyclopedia

Hull number is a serial identification number given to a boat or ship. A lower number implies an older vessel. The precise usage varies by country and type.

For civilian craft manufactured in the United States, the hull number is given to the vessel when it is built and forms part of the hull identification number, which uniquely identifies the vessel and must be permanently affixed to the hull in at least two places.

The United States Navy employes hull numbers in conjunction with a hull classification symbol to uniquely identify vessels and to aid identification. A particular combination of hull classification and hull number is never reused, and therefore provides a means to uniquely identify a particular ship. For example, there have been at least eight vessels named USS Enterprise, but CV-6 uniquely identifies the World War II carrier from all others.

It should be noted that the US Navy sometimes confuses the sequence of hull numbering. For example, the Navy built the last Los Angeles-class submarine as SSN-773; then built SSN-21 through SSN-23; and later resumed the original sequence with SSN-774 for the next class of submarines.

When a naval vessel is refitted for use as a different type of ship, a new hull number is sometimes assigned along with its new classification. Often the number remains the same, while the hull classification changes. For convenience, the combined designation, which is painted on the side of the ship, is frequently called the hull number.

Hull numbers are also used to identify tanks.

• United States Code of Federal Regulations, Title 33.
• USS Enterprise (CV-6) website
• Hull numbers for surviving Tiger tanks

• Pennant number

• Identification of Boats through the Hull Number