((a)) To the extent necessary, the Secretary shall remeasure a vessel to which this chapter applies if—
((1)) the Secretary or the owner alleges an error in its measurement; or
((2)) the vessel or the use of its space is changed in a way that substantially affects its tonnage.
((b)) Except as provided in this chapter or , a vessel that has been measured does not have to be remeasured to obtain another document or endorsement under chapter 121 of this title.