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Dive Knives

Dive Knives

Size

Typically, a Large Dive Knife has a blade over 5 inches, while a Medium Dive Knife has a 4 to 5 inch blade, and a Mini Dive Knife caps off at 2-3 inches.

• Large Dive Knives: Size is important, because a big dive knife is not always the best choice. Large dive knives can be awkward and heavy, hard to manipulate in a tight space without causing damage to yourself or your equipment. A dive knife is almost never used as a weapon, and it may be best to consider the practical application of your new knife before making a purchase.
• Medium Dive Knives: By far the most practical dive knife, a medium sized dive knife has the heft and mass you'll need without the ungainly length of some larger dive knives. Medium dive knives are convenient, and can often be strapped to a variety of easy-to-reach locations, including your BC, your arms, or your legs. The hilt is still long enough to get a firm grip, so you never sacrifice strength for size.
• Mini Dive Knives: For a compact profile, nothing beats a mini dive knife. With a 2-3 inch blade, a mini dive knife can fit anywhere you need it to go, including clamping it onto a hose for quick access. An important tip - make sure that the handle is longer than 2-3 inches, so that you can get a firm grip on the knife, even through thick gloves.

Shape

Typically, a Large Dive Knife has a blade over 5 inches, while a Medium Dive Knife has a 4 to 5 inch blade, and a Mini Dive Knife caps off at 2-3 inches.

• Straight or Serrated: The edge of your dive knife is an important concern. If you find yourself cutting plastic more often, such as a monofilament line and nylon rope, a straight edge is going to be more useful to you. A serrated blade for your dive knife, however, is best suited for sawing at natural fibers like rope and kelp. Many blades have a straight edge on the front and a serrated edge on the back, a useful feature for a variety of situations.
  
• Sharp Tip or Blunt Tip: A sharp tip is great for puncturing and cutting, and is used most often during spearfishing, including cleaning and dressing your catch. However, a sharp tip on a diving knife is inherently more dangerous, and is more likely to accidentally cut something you don't want it to. On the other hand, a blunt tip is great for prying, digging, hacking, and chiseling, and means you have to worry less about accidents that might break the tip of a sharp tip dive knife, or cause injury.
  
• Line Cutting Notch: A line cutting notch is a small spur projecting from the knife, one with a sharpened interior that is perfect for hooking around a line and cutting it swiftly. A line cutting notch on a diving knife is a very useful feature.

Material

• Titanium: Titanium dive knives are almost completely rustproof and corrosion resistant, owing to the fact that they contain no carbon for easy oxidation. A dive knife made of titanium will hold a sharp edge for multiple dives, and greatly cuts down on maintenance time.
• Stainless Steel: Most dive knives are made of steel; usually 300 or 400-series stainless steel alloys, with high carbon content for high tensile strength. The term "stainless steel" can be misleading, however. All stainless steel dive knives will eventually show some signs of rust, due to their high carbon content. Because stainless steel knives are not completely rustproof, they will require maintenance. It's important to rinse your dive knife with fresh water after each use, and to let it dry outside of its sheath. Coat with a light layer of oil or silicone after.
  • 300-Series Alloy: The lower the number, the more corrosion resistant the dive knife is, but the less able it is to keep a sharp edge. If you buy a 300-series alloy knife, you can spend a little less time on maintenance, but you'll have to sharpen it after a couple of uses. The convenience of a blunt-tip knife is that the sharpness is far less of a concern.
  • 400-Series Alloy: A 400-series alloy dive knife will hold an edge for longer, but is more susceptible to corrosion. It also may shatter if used as a pry bar. If you purchase a 400-series alloy knife you will need to wash and oil it after every use, but you won't have to sharpen it as often.

Shears and Accessories

A dive knife is not always your best option - sometimes a pair of diving shears can be just as useful, and much less likely to cause accidents or injury. A good pair of stainless steel safety shears can cut right through netting, line, kelp, rope, and even thin steel cable.

A neoprene dive knife wrap is another accessory you may need, allowing you to strap your knife sheath on your lower leg for easier access and safer retention. A rubber dive knife strap can do the same thing, allowing you to customize the most convenient place to store your knife.

If a dive knife alone isn't versatile enough for your needs, you can also find multi-tool toolpacks here as well, complete with assorted screw drivers, awls, open-ended wrench heads, and snips. You'll also find specialized line cutters, sheaths, and materials needed to care for and maintain knives and shears. See less