Under what circumstance can a Marine be confined to bread and water as a result of NJP?

The correct answer is that a Marine can be confined to bread and water as a result of Non-Judicial Punishment (NJP) if they are embarked aboard a Naval vessel. This practice stems from the Navy's regulations and traditions, which allow this form of punishment while at sea. The confinement to bread and water is considered a form of reduction in dietary provisions and can be used as a disciplinary measure during certain circumstances outlined within the naval and Marine Corps guidelines.

On naval vessels, the need to maintain order and discipline is paramount due to the unique environment and the nature of operations at sea. Therefore, confinement to bread and water serves as a means to quickly address infractions without the need for lengthy processes. Other circumstances, such as a Marine being a security risk or serving in a combat zone, do not specifically relate to the prescribed punishments while aboard a vessel, and approval from a General Officer is typically not necessary for standard NJP punishments.