The Ziploc Habit (I'll Die On This Hill)
Okay. This lesson is short and I'm not sorry about it.
We're going to talk about a sandwich bag.
I mean that. A regular gallon Ziploc, the kind that's already in your kitchen drawer right now. This is Low Key the cheapest, dumbest, most effective piece of gear in this whole class, and I bring it up every single time because I got burned once and I never want that to happen to you.
Why I care so much about this
I got caught in an afternoon storm coming down a canyon a few years back. Phone was already dead, which fine, that's a different lesson. But my paper map, the one thing I was actually counting on, got soaked through in about four minutes. Ink running, paper going soft, corners tearing when I tried to fold it. I still had my compass. I still sort of knew where I was. But trying to read a disintegrating map while rain is coming sideways is not a good time.
Since then, every map I own lives in a Ziploc the second I print it or buy it. No exceptions. It sounds too simple to matter, and that's exactly why people skip it.
What to actually do
- Get gallon-size freezer bags, not the flimsy sandwich ones. Freezer bags are thicker and the seal holds better. A few cents more, worth it.
- Fold your map to a size that fits with room to spare. Don't cram it in tight. You want to be able to see most of the map through the plastic without opening the bag every time you check it.
- Push the air out and seal it all the way, corner to corner. Half-sealed bags are how water gets in. Run your finger along the whole seam.
- Keep a dry pen or pencil in there too, if you're the type who marks up a map. I do. I'll circle a water source or jot a bearing right on the plastic with a dry-erase marker, then wipe it off later. Works great.
- Check the bag before every hike, not just when you remember. Bags get pinholes. They get a little crack in the seal from being folded the same way fifty times. Takes ten seconds to glance at it.
That's it. That's the whole lesson, honestly. But I want to fold in one more thing while we're on the topic of gear doing weird things to you when you're not paying attention.
While we're talking about gear failing you
I was trying to teach my sibling Amber a bearing once, out on a hike, nothing complicated. I handed her the compass, told her to hold it flat and level, and she did, right next to her big steel water bottle clipped to her pack strap.
The needle just spun. Slowly, lazily, like it was thinking about something else. I watched it for a second and figured it'd settle. It didn't. Took me a solid ten minutes of moving her arm around before I figured out what was happening.
Metal messes with the needle. Nobody tells you this when you buy a compass. Water bottles, keys, your phone, the metal frame on some packs, even a belt buckle if you hold the compass low enough. The needle isn't reading north anymore, it's reading whatever's closest and made of steel.
So: when you take a bearing, get the compass a good arm's length from anything metal. Set your water bottle down. Put your phone in a different pocket. It feels fussy the first few times and then it just becomes part of how you hold the thing.
The opinion I'll stand on
This connects to something I said back when we picked out compasses. The cheap baseplate compass beats the fancy one for beginners, and part of why is this exact problem. Fewer bells and whistles means fewer things to second-guess when the needle's doing something weird. You want to be asking "is there metal near this thing" not scrolling through a manual wondering if you broke a $60 sighting mirror.
Simple gear, kept dry, kept away from metal. That's most of the battle before you've even taken a real bearing.
Before next time
Grab a gallon Ziploc from your kitchen and bag up whatever map you've got, even if it's just the trailhead map from last lesson. Get in the habit now, before you actually need it. And if you're bringing a compass to our next session, leave the water bottle in a different pocket when we practice.
Thanks, Jason