(a) An existing vessel need not comply with §§121.402(c), 121.404, 121.410, and 121.602 of this part unless the cognizant OCMI specifically requires compliance due to the route or service of the vessel.

(b) An existing vessel need not comply with the requirements of §121.610 of this part until March 11, 2001, or 10 years after its keel was laid or the vessel was at a similar stage of construction, whichever is later.

(c) An existing vessel need not comply with the requirements of §121.710 of this part until March 11, 1997.