As maritime operations become increasingly digitalized, the Planning Maintenance System (PMS) aboard ships has emerged as a vital tool for managing sensitive information, such as maintenance schedules, navigation logs, and operational metrics. However, transmitting this data over open communication channels makes it vulnerable to interception, tampering, and cyberattacks. Existing cryptographic solutions often rely on computationally intensive mechanisms that are unsuitable for resource-constrained maritime environments, particularly in the quantum era. This article proposes a lattice-based system designed to secure PMS on ships in the quantum era. The proposed system leverages efficient lattice-based key exchange and authentication protocols to secure data against hybrid attacks, offering enhanced security without compromising computational efficiency.