Dive knives come in so many shapes, sizes, styles and functions. Remember, a knife used for diving is not a weapon—it’s a tool. In most circumstances, it will be your only tool. When choosing your dive knife you have the choice of a fixed blade or a folding blade. Fixed blades are the most common type of diving knife. Folding knives are more compact; however, they can be difficult getting open when wearing gloves. Things to consider when buying your dive knife are whether they are steel vs. titanium, blunt tip vs. sharp, straight edge vs. serrated, all determined on what type of diving you will be doing.