If there is a good chance you may end up in territory that is new to you, and some need to navigate and return to specific locations, you might want to toss in a couple of 3x5 cards and a pencil stub.

With a pencil stub and something to write on you can take notes so you don't have to remember which way you turned and how far you traveled. Under pressure human memory fails, gets confused, and things often come out backward.

On one hike there was a very distinctive tree I would pass on the right going in. But on the left going out. Or was it the other way round? I can picture it in my mind both ways because I've seen it both ways. I just can't remember for sure which is which and it defines a fork in the trail so it makes a big difference. This sort of thing is where having a note telling you which way can save you.

Under pressure, shy of food, slightly dehydrated, tired, worried, distracted, and with people dependent on you is when you need to take notes. Things get really tough and you can set up checklists. If you know you have to take the third fork to the left you could check off each fork in turn so you don't forget one. Sounds silly that anyone might lose count counting to three, but it happens. The human brain is creative and a very powerful tool for inference. It is a lousy recording device. With lives on the line don't count on your memory.

Pilots, and increasingly surgeons, rely on checklists.

Besides 3by5 card stock and a pencil are good tinder. Lots of uses.