major conversion
(C)designated a hazardous material undersection 5103(a) of title 49;(14a) “major conversion” means a conversion of a vessel that— (A)substantially changes the dimensions or carrying capacity of the vessel; (B)changes the type of the vessel; (C)substantially prolongs the life of the vessel; or (D)otherwise so changes the vessel that it is essentially a new vessel, as decided by the Secretary.