Salient points, Aussie.

This raises an important sidebar issue: say I'm on a cruise, and I see someone I think is in distress.

Realistically, what actions and language do I use to ensure that the ship's command structure (rather than the dept. of concierge) receives the information? All this, preferrably, without being tossed in the brig as an obvious troublemaker and disturber of the peace?