((a)) ** .—** If acquisition of an obsolete vessel under this chapter occurs when the owner contracts for the construction or purchase of the new vessel, the Secretary of Transportation shall apply the trade-in allowance to the purchase price of the new vessel rather than paying it to the owner. If the new vessel is constructed under this subtitle, the Secretary may apply the trade-in allowance to the required cash payments on terms and conditions the Secretary may prescribe. If the new vessel is not constructed under this subtitle, the Secretary shall pay the trade-in allowance to the builder of the vessel for the account of the owner when the Secretary acquires the obsolete vessel.

((b)) ** .—** If acquisition of the obsolete vessel occurs when the new vessel is delivered to the owner, the Secretary shall deposit the trade-in allowance in the owner’s capital construction fund.