I got pulled out of line while boarding HAL's Zuiderdam (which was right next ot the QM2, nice ship!), they were QUITE upset about my tools in my carryon: a small knife, pliers and two screwdrivers. They gave them back to me the very last day with a letter explainging that they were considered "weapons."
Moral of the story: no one cares what' not in your carryon. Stick it in the luggage and no one will care at all. When I picked up my tools, they pulled out a box with all sorts of confiscated stuff in it, including bout 5 dive knives
But, on the dive boat a few people had dive knives with them. "Oh, it was in our packed luggage" they told me.
What was really funny, they didn't complain about the knife at first, they complained about the "wire cutters," needle nose pliers with a small cutting thing near the fulcrum. I told them "No, I don't have any wirecutters" and they ran it through again, and asked again, and I remembered then that I had pliers, and maybe they meant pliers when they said wirecutters. It didn't make them very happy, I think they thought I was trying to sneak them through.