(a) A manufacturer of a marine SI engine family with an in-use compliance level below the applicable FEL to which the engine family is certified for a given model year may bank positive in-use credits for that model year for use in in-use averaging and trading.

(b) A manufacturer may consider credits banked 30 days after the submission of the report required by §91.1309(a). During the 30 day period EPA will work with the manufacturer to correct any error in calculating banked credits, if necessary.