A Diver’s Companion: Picking the Best Dive Knives

Divers are action stars come to life—we leap from boats, free fall to great depths, and swim with the largest creatures in the ocean. And like your favorite action hero, we also carry our favorite knives with us every time we enter the water.

Dive knives are cool-looking and very sharp, but we don’t use them for action combat. In fact, we refer to them as “dive tools”, and mostly use them to make sure we don’t get tangled in any number of possible snares, both natural and man-made. When selecting the right dive knife, we will need to consider a few features such as materials, blade length, and sheath.

Best Dive Knives - Comparisons

The Promate titanium knife is a great tool for almost any diving situation. The 4 3/8-inch blade is made from lightweight and corrosion-resistant titanium. The handle is molded from rubber to offer a comfortable grip with or without gloves. The light weight of this knife makes it feel almost as if you aren’t carrying a knife at all, but it is strong enough to take on fishing line, kelp, or even help rescue a trapped animal from an errant net.

The blade and butt of the knife are both made of titanium, which is naturally resistant to corrosion, which means you’ll need to spend less time caring for this knife. The low maintenance is one of the best features of the Promate. According to the manufacturer, this knife requires little to no maintenance, so simply rinsing and letting it air dry is enough to keep it in pristine condition—this also means more time enjoying the sun and less time scrubbing your knife.

The sheath of the knife has adjustable straps that allow you to place the knife wherever it’s most convenient and comfortable for you while diving. I like to put mine on the outside of my calf where I can easily reach it at a second’s notice. The straps are long enough that I can use them on a thicker suit in cold water, but not so long that they are a nuisance in warm water.

The blade comes with either a blunt tip or sharp tip, depending on your preference. The top side of the knife has serrations and a line cutter.
The knife is held in place by two clips in the sheath, which hold the blade in place reasonably well even when head down in the water.

Simplicity is the key to the Lima knife. The 2.95-inch blade is held in place by a minimalist handle—sure, you won’t win any fashion contests with this blade, but you will have an easy-to-use and comfortable handle that gets the job done.

The blade is made from stainless steel and provides surprising durability against salt water. You do need to rinse and dry the blade adequately to make sure it has a long life of service.

The size of this knife is a specific design feature that makes the Lima very versatile. The less than 6-inch total length means that you can place this knife basically anywhere on your person.

The sheath includes a two-button lock system that keeps the knife securely in place to prevent accidental unsheathing, but the lock can be opened easily with the two buttons to remove the knife from the sheath. While this can be a little tricky with gloves, the locking system is surprisingly fast.

Atomic aquatics lives by the motto “if you’re going to do something, do it well”, and this notion carries cleanly into their Ti6 dive knife. The full tang of the blade is made from corrosion-resistant titanium, meaning you won’t have to spend time and energy cleaning the blade after a dive. You also don’t need to freak out if you forget to clean the knife before your flight home—the titanium shrugs off the salt water’s bite with ease.

Cleaning the Ti6 is as easy as a simple rinse and thorough drying, you just need to remove the end cap. Mind you, the inside of the handle can still develop must and mold if you don’t clean it out once in a while, so make sure to pop off the cap to ensure that your knife is clean inside and out.
The blade is curved to create a good-looking blade shape, and holds its sharpness pretty well. The knife has the typical serrations found on most dive knives, the difference is that the serrations are a little broader and tooth-like. The line cutter is on the sharp side of the blade, making line cutting feel natural and smooth.

The sheath of this knife has a lock to hold the knife in place, and adjustable straps to give placement options. The handle is molded to the shape of fingers, making removing and holding the knife easy and quick.

Also Read: Best Throwing Knife – Top Selections for Expert & Beginners

This entry is a little different from the other knives on the list. Thus far, we have featured fixed blade designs with an included sheath—the Pacific Salt knife, however, is a folding knife. The advantage of this knife is that it has a clip system that allows you to attach it to your equipment. The folding design also reduces the chances of accidentally stabbing or cutting yourself while getting it ready, or putting it away.

The blade is made from H1 precipitation-hardened steel—the technology behind this knife uses nitrogen to harden the steel, which makes these blades very strong. This process also makes the steel more resistant to rusting and pitting. While unconventional, this blade is a good choice for divers looking for consistency and durability. 

On the back side of the knife is the clip that can be easily manipulated with either the right or left hand. The blade is serrated along the edge, which makes it perfect for cutting away entanglements. The blade length is 3.8 inches, and the overall length is 8.6 inches—this gives you enough knife to get out of trouble without being a cumbersome nuisance. Its light 3-ounce weight makes it feel like you aren’t carrying a knife at all.

The Zip knife is a tactical-style knife for someone who wants a blade that is just as good out of the water as it is under the blue waves of the ocean. At 8.3 total inches, with a 3.7-inch blade, you have a complete blade made from 440C stainless steel.

The pointed tip of the blade has two edges that give it superior cutting power in any direction. Along the bottom of the blade area short serrated section and line cutter which further add to the slicing versatility of this knife. The finger molded handle makes the knife comfortable to hold, and gives enough grip to cut free of thick kelp or clean the fish you caught on your last dive.

The sheath is made if durable ABS plastic with a clip lock that holds the knife in place while you have it strapped to your body or equipment. The lock is easily disengaged with your thumb, which puts the knife in a ready position right out of the sheath.

Two straps accompany the sheath that allow you to place the knife on your arm or leg comfortably enough. The 8-inch length isn’t a problem for me to strap to my lower leg—it isn’t as easy to strap to a BC or hoses like some of the other knives, though.

Which Dive Knife is for you?

Blunt vs. sharp tip

The end of your knife gives you two options. While a sharp tip is useful for stabbing or penetrating a target, the second option is getting a blunt tip, which basically looks like the knife was clipped off a little early— however, the tip is still tapered to an edge on blunt tip knives.

Most of the knives on our list come in both varieties, but as an experienced diver I recommend going with the blunt tip. Sure, it doesn’t look as cool or is as intimidating as the sharp tip, but the higher degree of safety makes it worth the slightly lower coolness factor.

Blunt tip knives are safer because you don’t have the risk of accidentally stabbing yourself or dive equipment when sheathing and unsheathing them. Dive knives aren’t for stabbing after all, no matter how glorious you think facing off with a shark in knife-to-tooth combat would be.

The other reason I recommend going with a blunt tip is for hunting. Many of the best seafood meals are made from shelled animals that cling tightly to rocks, and the tapered end of the blunt knife will allow you to get down underneath the shellfish and pop them off the rocks. Many a diver has broken the sharp tip off their knife in their struggle to grab a scallop or urchin off a rock face.

How does the knife mount?

The next thing you need to consider is how the knife will actually attach to you or your equipment. The knives on our list offer one or more of the following three ways to attach the knives:

• Straps – The most common method of mounting your knife is with a pair of rubber straps that you can wrap around your arm or leg. Straps come in varying lengths, and you need to count on having longer straps if you plan on strapping the knife to your thigh.
• Clip – Some knives or their sheaths have a clip that you can slip over a weight belt, BC strap, or other similar location. This type of attachment is the fastest one, but it is also the least secure. If you choose a knife with a clip, I would recommend rigging a back-up system to help prevent losing the knife.
• Hose mounted – Smaller knives like the Cressi Lima have a mounting system that allows them to attach to one of your regulator hoses. This kind of mount is more permanent, which is a nice way to avoid having to attach and detach the sheath for every dive. I recommend putting in on your inflator hose or gauge hose, not on your breathing hoses.
• Bonus – BC Grommets. Some BCs have metal grommets that you can attach a knife to. This is another long-term solution to attach your knife. Certain brands of knives are designed to specifically pair with certain BCs.

Knife Care

Always clean your knife after every dive by thoroughly rinsing and drying it off completely. To make sure the knife resists rust, corrosion, or pitting, you may also want to coat it with a treatment to protect the blade from salt water. There are a number of treatment coatings available that will ensure your knife lasts as long as your diving career.

Final Thoughts

Having a dive knife is an essential part of dive safety. While you may not be using it to slay wicked henchmen, having a strong and reliable knife made from stainless steel or titanium will help you escape almost any net, fishing line, or pesky kelp stock. 

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