In "Gear and Equipment", section "Selecting the Best Sharp", it says:

...a survival knife should have a blade at least four inches long, but no longer than six inches...

The problem is, 4 inches isn't legal everywhere, and it's usually quite a bit less (2.5" in Missouri, IIRC).

How much are you giving up by carrying a smaller knife? What sort of situations would you find yourself in that a knife with, say, a 3" blade wouldn't work for, but the longer knives recommended in the guide would? Is there any way to compensate for the lack of a longer blade? Maybe by carrying multiple small blades?