R.I. Gen. Laws § 30-13-23: Confinement in default of payment of fine.

All courts-martial shall have power to sentence, in the alternative, to confinement in default of payment of a fine imposed by the court. In these cases, the court shall fix a reasonable time within which the fine shall be paid; provided, however, that the sentence of confinement shall not exceed one day for each five dollars ($5.00) of fine imposed.