Which of the following factors is NOT relevant when assessing the boarding team’s strategy?

When assessing a boarding team's strategy, the visibility of the boarding location is not considered a relevant factor. This is primarily because the other listed factors—such as the cooperation of the master, the master's familiarity with the vessel, and safety concerns—directly impact the effectiveness and safety of the boarding operation.

Cooperation from the master is essential as it can facilitate smoother interactions and compliance with the boarding team's requests. The master's familiarity with the vessel contributes to understanding its layout, potential hazards, and the ease of conducting inspections. Safety concerns are always paramount in any boarding operation; they dictate how the team approaches the situation and the precautions that need to be in place.

In contrast, while visibility might play a role in the logistical planning of approaching a vessel, it does not directly influence the boarding team's strategies or their operational effectiveness. Thus, it is less critical compared to the other factors that significantly impact the boarding process.