Shows like Man vs. Wild and Survivorman are increasingly popular as city dwellers imagine what it would be like to be stuck out in the wild forced to survive on your own wits and whatever you might have in your pocket.

One tool that these "professional survivors" always have on hand is a good survival knife.

With a good survival knife you can cut green limbs to use as splints for broken arms, dig into logs for grubs and bugs to eat, cut lengths of vine to tie a raft or shelter together and even as a fishing spear when attached to a straight pole that you have cut with the knife.

You want a survival knife that is not overly heavy, since you will be carrying it in your backpack.

It should have a large shank guard that keeps your hand from slipping down the knife onto the blade when using it to dig our gouge. The last thing you want while in the wilderness is a wounded hand from a poorly designed knife.

Another feature it should have is a container within the handle where you can keep a few waterproof matches or a magnesium fire starter, a length of line and fishhook and any other survival objects you can fit such as a couple of water purifying pills. The cap on the end of the handle should have an "o" ring that keeps the contents of the handle dry in case you end up in the water.

A good survival knife should also have a small compass that is built into the handle in case you loose your primary navigational compass.  Steel knives will interfere with a compass so in order for the compass to be useful it needs to be removable.

Survival knives may also feature a saw tooth blade on the back side which is handy to cut small limbs.

The sheath should be made of leather or tough nylon and have a sturdy fastener that keeps it from falling out. It should be double stitched of nylon or other synthetic thread.

You should keep your survival knife sharp at all times. Dull knives cause more injuries than sharp ones do. That is not just an old saying, it is a fact. When a knife is dull the user will have to apply more pressure to make a cut and may end up stabbing themselves from using too much force.

A good survival knife has saved many a life over the years. Anyone traveling into the back country should carry one.