It is really important that owners of historic narrow boats register them with National Historic Ships.
Registration criteria are here: https://www.nationalhistoricships.org.uk/page/nhs/registration-criteria
To register, complete the form on this page: https://www.nationalhistoricships.org.uk/the-registers/register-your-vessel
To write a Statement of Significance, read the guidance here: https://www.nationalhistoricships.org.uk/the-registers/about-the-registe...