Survival knife ie: Dog Father. To save weight and room it would replace a small axe or large hatchet and a folding shovel or U-Dig-It trowel plus other knives that I carry in non-survival situations.
My survival knife is used to make wood shavings, limb trees, and split 6" to 8" logs for fires. If I'm not worried about leaving a "footprint" it is used for brush clearing - moving the undergrowth a few feet away from camp. The survival knife is used to prepare fish and small game for meals. It must also be able to dig worms for bait and holes for waste disposal. My survival knife also finds its way as a pry bar occasionally and is use for various precision field work that comes up. Finally it also serves as an offensive and defensive weapon if need be. Of course don't forget it has to be easily resharpened in the field. Wow! I'm worn out just thinkings about it. There are very few knives that will fulfill all the above and when you find one it will more than likely set you back a car payment. <img src="/ubbthreads/images/graemlins/eek.gif" alt="" />