What is the appropriate action for a boarding officer upon discovering illegal substances on board?

The appropriate action for a boarding officer upon discovering illegal substances on board is to secure the substances as evidence and notify the appropriate authorities. This action is critical because it ensures that the illegal substances are handled in a manner that preserves their integrity as evidence for any potential prosecution. By securing the substances, the boarding officer maintains a chain of custody, which is essential for any legal proceedings that may follow. Furthermore, notifying the appropriate authorities ensures that the situation is handled by the proper legal and enforcement channels, which may include law enforcement agencies that specialize in drug interdiction.

Securing evidence also reflects adherence to legal protocols and protects the officer and their agency from any legal repercussions that could arise from mishandling illegal substances. In contrast, releasing the substances to the crew would enable the illegal activity to continue, while disposing of them overboard would not only be irresponsible but could also constitute destruction of evidence. Confiscating the substances for personal use is unethical and illegal, as it involves misappropriation of seized items.