What should the on-watch personnel prevent when a suspicious item is discovered?

When a suspicious item is discovered, on-watch personnel should prioritize safety and security. Preventing anyone from approaching the item is crucial to ensure that it does not pose a risk to personnel or the vessel. Allowing individuals to get too close could lead to injury or create a larger security threat if the item is hazardous or potentially explosive. By restricting access, personnel can maintain a safe perimeter, minimizing risk while further assessments or investigations are conducted.

The other choices also play a role in an effective response plan, but the primary focus should be on securing the area around the suspicious item to prevent any potential harm or escalation of the situation.