We all know that a knife in hand is better than none when in a survival situation. But there’s one more thing you should know: a dull knife (even if it’s the best survival knife in the world) just won’t cut it… or slice, chop, or hack. If you find yourself in a life-or-death situation, you’ll need to be able to rely on this tool. And though you’re still better off with a dull knife than no knife at all, using it will mean loads of frustration – something that you may not be mentally equipped to handle given your circumstance. If you’re lucky, you might have thought to bring a sharpening tool with you before you found yourself lost in the wilderness. Unfortunately, we all can’t rely on luck (you were unlucky enough to find yourself in a survival situation, remember?).  So, how does one sharpen a survival knife in the bush? We’ve listed three ways you can do so with only the materials you have in hand.

Sharpening a Knife in a Survival Situation:

Create your own whetstone.

Find small coarse stones that you'll find in rivers and crush them into a pulp using a big stone. Once the stones are like mush, get a piece of living wood (about as thick as the handle of a baseball bat) and strip off its bark. Wet the wood a bit and then rub the pulp around it using your hands. This "contraption" now serves as your DIY whetstone. Draw the knife's edge across the wood until you reach your desired sharpness. To ensure that you get the most out of your makeshift whetstone, be sure to hold the blade perpendicular to the wood the entire time you’re sharpening it. If you need to see how it’s done, you can check out a video of Bear Grylls making his own whetstone here.

Use a flat, smooth rock.

If used properly, a flat, smooth stone, preferably a sandstone or any other sedimentary rock, will easily sharpen your survival knife. The quality of the blade’s sharpness may not be as great as that provided by a real sharpening stone but since you’re in a survival situation, it is definitely more than adequate for your needs. You can easily find these stones in streams, rivers, lakes, ponds, and even under waterfalls. Sedimentary stones are preferable over other types of flat, smooth stones you’ll find because the small, abrasive grains that make up these rocks enable faster cutting action. To sharpen your knife, glide the stone along each side of the knife’s edge for an equal number of times until you the knife is as sharp as you want it to be.

Strop your knife with your belt.

Stropping is a technique used to sharpen a blade's edge by polishing it and smoothening out the microscopic burrs found along the edge. To use this method, you’ll need to use a leather belt or a piece of rubber. If a belt is no longer Hold the strop nice and taut. Drag the blade's edge back and forth on the strop while holding it at a very shallow angle. Be sure to draw the blade away from the cutting edge so that it won't cut/slice the strop or you while you perform this task. If you don't have a leather belt at the moment, you can use the edge of the rubber sole of a boot as an alternative. To see how it’s done, check out this video: