You can register your boat with the UK Ship Register for use at sea.

There are several reasons for doing this and the web link below outlines the background.

https://www.gov.uk/register-a-boat/the-uk-ship-register

In relation to boats from members of EDYC we have an exemption from the

Registration marking regulations which states that vessel’s Port of Registry must be permanently marked on its stern. The exemption is valid until 31/12/2023

The exemption certificate is available via this link