Video summary A ceramic rod can work well for sharpening a recurve blade. It lets you get into the bottom of the recurve, where it’s hard to reach wit [See the full post at: Recurve rod technique]
The benefit of a recurve blade is that the additional curvature lengthens the cutting edge relative to the length of the blade. The edge line looks sort of like the letter “S”. If you stretch out that “S”, you would see how long it really is compared to if your knife edge was straight like an “|”.
It also give multiple points of contact against the material you are cutting, similar to how serrations work and give good cutting ability. Think of it as single stretched out serration. This makes recurves great for slicing rope, or food.
Many machetes and other brush clearing knives implement a curve of some sort to extend the length of the blade over the material they are slicing through.
The one downside to recurves though is they are slightly more difficult to sharpen than a straight edge blade. But this video shows that it’s not too bad once you know how to do it.
You can read more about recurve knives and things to look for in a survival knife in the Best survival knife article.