- The registered number of a flat or boat shall remain in force as an identification number throughout the whole working life of the flat or boat unless(a)the flat or boat remains unlicensed for a period of 3 years;(b)the flat or boat is condemned by the Commissioners' Boat Surveyor as unfit for further service;(c)the number branded on the flat or boat becomes obliterated and cannot otherwise be traced, and(d)the dimensions of the flat or boat are altered.
