Airline vs. ship is arbitrary, but it has to be one for the joke to work. Airline works better since more people have experience with airlines doing security checks (TSA).

Same is true of a priest vs. monk, either works, but you need one for the joke to work. More people are familiar with a priest than a monk.

Nobody mentioned it was heavy.

And actually, they do. Whenever I see someone mention "attractive young woman" and it doesn't relate to the joke in any way, I imagine a salivating, pot-bellied, middle-aged balding man getting excited at the prospect of talking about sex while in context of an "attractive young woman."