What special care must you take with your hull identification number?

The hull identification number is the twelve or fourteen character serial number that uniquely identify a boat built after 1972. It is usually inserted by the boat's manufacturer. The number has a safety purpose. You must be careful not to remove, alter or deface the number; for this is illegal. The number should be written down and put in a separate place [not in the vessel]; this is necessary in case the vessel is stolen or warrant issues arise.