What is a British Registered Vessel?

We rarely see Part 1 registered craft, these are controlled by the Maritime and Coastguard Agency https://www.gov.uk/government/organisations/maritime-and-coastguard-agency. Here are some guidelines as to whether it is worth registering. If the vessel is over 24 meters in length, it is owned by a company, a lender has taken security over the vessel and requires a marine mortgage or charge to be registered against it or the craft is to cruise on international waters for substantial periods of time. The procedure for registry is substantial as survey reports to produce tonnage certificates etc have to be undertaken. The certificate of registry has to be renewed every 5 years or it will lapse.