Nothing wrong with entetainment in the kit.

You might even thing of some of the smaller musical insterments. A Harmonica springs to mind at the top of the list. What you don't play? You can always learn. It might drive others crazy but learning to play would kill a lot of time. Playing a tune might pass a lot of waiting time. It might even get you found by the sound.

The old joke with a deck of cards is if you get lost. Sit down a start playing solitair. Soon someone will show up and tell you to play the black ten on the red jack.