In UK law, you can carry a knife without any reason if: 1. It is folding (non-locking) AND 2. Blade length <3" A fixed/locking blade of any length (<=>) 3" requires good reason to carry. Camping is a good reason. I use a Kuhn Rikon paring knife in a plastic sheath, and take a flexible plastic cutting board. On smaller and non-cooking tours I just use my Swiss Army knife for food, but cleaning it is harder than a paring knife. I prefer to use separate blades for food and dirty work.