A knife is not strictly necessary on expedition but is certainly a useful addition to your gear.

A Multitool will be more use than just a plain knife but this is down to personal preference, Victorinox do a great range of ‘swiss army’ type knives and one of these is probably the best to go for if you decide to carry one.

Safety has to be a big priority while using any sort of sharp tool, if you need to use it to cut something then be sure to always cut away from yourself and other people, a serious cut could mean the end of your expedition.

Leatherman also do a great range of knives but tend to be a little heavier, be careful not to carry so many tools they end up weighing you down, remember that light is best as you will have to carry everything on your back for up to four days and the lighter your pack the better.

Gerber do a range of knives and other accessories that are endorsed by Bear Grylls and some of these items are well worth looking at but can be a bit on the expensive side.