Several BMSE surveyors offer Tonnage Measurement via the YDSA or MECAL Certifying Authorities respectively. This survey is required for obtaining Part 1 British Registry or registration with other Red Ensign Group flags.
Tonnage measurement is a brief survey that requires a few measurements to be taken by an authorised surveyor and can be done while the boat is in the water. Pricing is often fixed by the Certifying Authority (plus travelling expenses). You will need to make an application via the Certifying Authority before the survey can take place. Your surveyor will guide you in this.