The Builder and Buyer ratify and affirm that the Shipbuilding Contract is in full force and effect between them as at the date of this Addendum but, unless otherwise agreed, the Shipbuilding Contract shall become null and void and the parties shall be discharged from their respective obligations if the Buyer has not delivered to the Builder within close of business on 30 December 2011 the guarantee in favour of the Builder described in Clause V.4 of the Shipbuilding Contract (as amended in this Addendum).