(a) Prelaunching period. This period is from the date and time the first material destined for inclusion as part of the vessel becomes at risk at the shipyard of the builder to the date and time the vessel first becomes water-borne after launching.

(b) Postlaunching period. This period is from the date and time the vessel first becomes water-borne after launching to the date and time of delivery of the vessel by the builder.

(c) Portions of periods. A vessel may be insured for a portion of either period as cited in paragraph (a) or (b) of this section at the sole discretion of the Maritime Administrator.