Some things are easy to detect — like a poser in uniform. You can spot them a mile away. Other things are like ocean tides and can shift without warning. Whether you're a civilian in the wild or a soldier in the field, it's impossible to anticipate every situation. But the difference between not knowing and survival is preparedness. Check out these four gear-based survival hacks. All you need are the right tools and a little savvy.

1. Need a fire? Use your knife. Cut the bullshit.

Get a knife that can do double or triple duty. Pocket knives are great, but heavy duty knives that hold up outdoors and have other features- like fire starters, make things like matches inconsequential. Magnifying glasses are cool and so are batteries, but as a gearhead you're less likely to carry those on body. Stick with a fixed-blade like the SOG Series SEAL Strike knife that can harvest kindling and start the fire all on its own.

Benchamde Pocket Knife in Hand  VSSOG Fixed Blade Knife in Hand

2. Put the shirt on your back to good use. 

Boiling water for purification isn't always an option. Collect safe drinking water with a t-shirt or bandanna by soaking up rainwater or dew from various plants and wringing it out into your canteen or water can, it takes some time but if you're far from a freshwater source and without a way to boil water, it's your best bet to stay hydrated and a hell-of-a-lot better than drinking your own urine!

Bear Grylls MEME - Sun's Going Down - Better Drink My PISS

3. Bite the bullet and make a whistle. 

If you're in deep brush or heavy terrain, help potential rescuers hear you before they spot you by using a bullet cartridge to make a survival whistle. All you need is a casing, a rock for sanding and sawing, and some patience. Check out this video for a how-to tutorial:

4. Use water and wire to find your true north.

The sun rises in the east and sets in the west, that much you know. But at high noon and surrounded by trees, hell if you know which way is which without a compass. Make your own using water, some wire, and the earth's magnetic field. This tutorial shows you how:

Got other survival hacks? Share them with us in the comments.