yeah, after re reading, I wonder if it is a straight knife. Those definitely don't usually come in two inch blades. Also, though I can't find the open carrying of a weapon in SC to be illegal (other than a firearm in the opening sections of the code), I have been told that it is not allowed.
It appears that SC is one of those states that allows only permits for firearms, not edged weapons. Beats me. A good belt knife is a good tool.