46 CFR §295.22

1. (a)Time frames. A Contractor that has been awarded a MSP Operating Agreement shall commence operations of the Eligible Vessel, under the applicable agreement or a subsequently renewed agreement, within the time frame specified as follows:
   1. (1)Existing vessel. Within one year after the initial effective date of the MSP Operating Agreement in the case of a vessel in existence on that date and after notification to MARAD within 30 days of the Contractor's intent; or
   2. (2)New building. Within 30 months after the initial effective date of the MSP Operating Agreement in the case of a vessel to be constructed after that date.
2. (b)Unused authority. In the event of a termination of unused authority pursuant to paragraph (a) of this section, such authority shall revert to MARAD.