Dive knife

Your Scuba Diving Knife

A dive knife is a general tool and safety device. In the latter case, you use it in the unlikely, but possible, situation that you’re entangled and need to free yourself. It is not a weapon.

Also known as : blade, shears, cutters, zip knife, z-knife, EMT shears

Required features

Sheath with retainer – A dive knife must have a sheath for mounting it on your equipment or body. The sheath must hold your knife securely, yet allow you to release and secure it with one hand. Some sheaths come with straps to allow you to wear it on your leg, etc.

Smooth and serrated edge – Sometimes you need to slice; sometimes you need to saw. Choose a knife that offers both.

Desirable features

Holds an edge – It’s easier to get a super sharp edge on softer steel and easier to lose it. You don’t usually need to shave with your dive knife, so a harder metal is a better choice.

Metal handle butt – On larger knifes, a metal handle butt doubles as a hammer. This comes in handy if you need to get your buddy’s attention by banging on his head . . . err, on your scuba tank. This isn’t a common feature on small, compact knives because they’re too small for pounding.


Optional features

Special purpose knives – Z knives (a.k.a. zip knives) are hooks with blades especially suited to cutting fine line. These are popular with wreck divers and cave divers in addition to a larger knife.

Knives that aren’t knives – Increasingly common are dive tools (more like crowbars with cutting edges) and special dive shears. They’re safer to use, more versatile and less likely to be restricted by law.

Titanium – Most dive knives are made of stainless steel, “less” being the operative word. That is, they “stain less” than something else like pig iron dipped in sulfuric acid. Even stainless steel rusts, but titanium, while much more expensive, lasts forever, or until you lose it.

How to choose a dive knife

Dive knife choice is a matter of preferences.

  • If you travel a lot, a small knife or shears are your best bet. They’re not likely to cause legal issues (knives are regulated in some areas) and they don’t add a lot of weight.
  • Wreck divers and cave divers usually carry more than one knife.
  • When choosing your knife, consider where you’ll wear it. Sometimes that dictates what you buy.


  • When traveling by air, don’t put your knife in your carry on luggage. Yes, it has happened.
  • It is not a weapon. A knife is important safety equipment. You don’t carry it as a weapon, but it can hurt people if you’re careless. Own and use it responsibly, respect it and keep it away from children.