In modern maritime communication, although UAVs provide better line-of-sight and data transmission capabilities, ensuring secure and reliable transmission has become increasingly difficult due to unstable channel conditions and the ever-present threat of eavesdropping. This work considers a scenario in which a formation of UAVs communicates with USVs on the sea surface in the presence of eavesdroppers (EDs). To prevent eavesdropping and ensure the safety of the UAV formation, a distributed control strategy based on Control Barrier Functions (CBFs) is introduced. Unlike previous methods, the proposed CBFs are suitable for dynamic maritime environments and can easily adapt to various control constraints, such as collision avoidance and eavesdropping prevention, as discussed in this paper. The simulation results demonstrate the stability of the control strategy, providing new insights for the use of UAV-based systems in critical applications such as military operations, rescue missions, and marine transport.