Let me be clear. The significance of a knife, especially a big knife (blade over 4" in length) in a "survival" situation is way overrated. I routinely carry at least one knife, but I have met every outdoor situation capably with something like a SAK or a multitool. Money spent on the typical large (5 inch or bigger) survival knife is essentially money wasted, money which would be better allocated to other more basic survival items, like a good fire making kit, basic shelter gear (especially a lightweight tarp) a FAK and FA training, and so on. You will do just fine with a moderate size Swiss Army or Mora knife, especially if you can keep it sharp. The SAK has the advantage of being something you can can and will carry just about everywhere;hence it is likely to be the blade available when things go off track.

It's not that I don't like knives; I own a bunch, including a couple of the large bladed types I am ranting against. I rarely carry them, because they are just too heavy and cumbersome for what they can accomplish.

We have all seen too many Tarzan and Rambo movies. They are Hollywood and I am speaking from a real life perspective.