Which punishment is NOT allowed for an E-4 during a commanding officer's NJP aboard ship?

Confinement to bread and water is not an allowable punishment for an E-4 during a commanding officer's non-judicial punishment (NJP) aboard ship. Under the Uniform Code of Military Justice (UCMJ) and Navy regulations, the types of punishment that can be imposed by a commanding officer at NJP are limited for enlisted personnel, especially for those below the pay grade of E-5.

Specifically, confinement to bread and water is considered a form of punitive treatment that is not authorized at NJP and is more severe than typical disciplinary actions permissible for lower ranks. Other forms of punishment that may be reasonable and authorized include extra duties, reduction in rank, or loss of pay, as these are more appropriate disciplinary measures aimed at correcting behavior without imposing overly harsh conditions. The intent of the regulations is to maintain discipline while ensuring fair treatment of service members.