46 CFR §68.17

1. (a)Vessels employed subject to the Act are entitled to operation only in the coastwise trade and only to the extent described in paragraphs (b) and/or (c) of this section.
2. (b)A vessel owned by an 883-1 corporation may engage in coastwise transportation for hire as a service to a parent or subsidiary corporation as defined in § 68.3. Such transportation for hire must be between points of the United States, including territories, districts, and possessions thereof embraced in the coastwise laws.
3. (c)A vessel owned by an 883-1 corporation may be operated under demise or bareboat charter to a common or a contract carrier subject to 49 U.S.C. chapter 101 if the corporation is a U.S. citizen as defined in 46 U.S.C. App. 802.
   1. (1)Such common or contract carrier may not be connected either directly or indirectly by ownership or control with the 883-1 corporation.
   2. (2)The demise or bareboat charter must be at prevailing rates.
   3. (3)The vessels under a demise or bareboat charter may not be used in non-contiguous trade.