5 Best Diving Knives 2018: A must-have Diving gear

By Kevin Arnold | Fishing

May 21
best Diving Knives

Introduction

The diving knife is must-have gear for all those “just-in-case” dreaded situations. If you are a newbie, it is good to have your best diving knife to help you in emergency situation beneath the waves. And, even if you are a professional diver, you will need a good dive knife to slice through rope, vegetation, lines and other marine stuff that entangles around your leg or arm.

When underwaters, you cannot ask for help, and it will be hard for your fellow diver to recognize your situation as it is quite dark around. Keeping that in mind, it is always a smart move to keep yourself geared up to rescue yourself.

Now, there is a wide range of dive knife models rushing through the market. Which one to choose?

This guide has been put together to help you find your best diving knife for 2018. Let’s get to it.

​Name of product

Handle size

Blade size

Rating

​Price

​Aqua Lung Argonaut Diving Knife - ​Best Diving Knives

​4.8”

​4.8”

Spyderco Atlantic Salt Knife  Best Foldable Diving Knife

​4.5”

​3.5”

​Promate Scuba Dive Knife

​5”

​4 ⅜”

​PROMATE Barracuda Knife

​4.5”

​5”

​Atomic Aquatics Ti6 Dive Knife

-

​​4”

Reviews of the Best Diving Knives 2018:

Aqua Lung Argonaut Diving Knife - Best Diving Knives

Aqua Lung Argonaut Diving Knife

First up in the line is this Argonaut Dive Knife made by a high-ranking brand viz. Aqua Lung. Designed as one of the best diving knives amongst its competitors, Argonaut outshines in its toughness and performance. It has been uniquely crafted with the approval of “world’s eminent maritime commandos.”

Durable design

Argonaut has been shaped from 4 mm thick single-piece of Titanium, and this is just the kind of knife every diver needs to wedge throughout the adventures. Titanium makes it light, durable and rust-proof.

The handle is wrapped, twice, with a 5 mm Nylon parachute cord (7 feet long) to offer excellent grip when underwaters. If you wish, you can rewrap it as you’d like in your style. The wrapping starts ½” from the hilt so that there’s a spot left for the forefinger grip.

The 2mm thick sheath provided is made from hard Kydex (just as in firearm holsters) and is heated & thermoformed to hold the knife snugly, but also allows easy drawing when pulled.

The blade features both serrated as well as smooth edges, which is just sheer badass.

Blade Design

Argonaut has Spartan as well as Blunt Tip shape options for the blade. The Spartan configuration is the best one in the market, especially for spearfishing. If you seek more utility, Argonaut’s “Blunt” with a blunt chisel-like the tip is also optimal.

Both Blunt tip and Spartan tip blades come with rounded die-cut serrations on one side to avoid snags on the rope.

Apart from this, there are several options for mounting as well.

The metal is treated with black EDP coating for enhanced durability, then was sharpened and laser etched with “Aqua Lung” logo. At the butt of the handle, there’s a sharp tactical tool that can be used for crushing, braking, and hammering.

Things We Liked

  • ​Titanium construction
  • Comes with an aircraft-grade sheath
  • Two blade options: Spartan and Blunt
  • Serrated and smooth edges provided
  • The butt of the handle is sharpened to use as a tool
  • Excellent grip

Things We Didn't Like

  • ​The sheath does not lock-in the knife; You might lose it underwaters

Customer Reviews

Customers have found Aqua Lung Argonaut to be one of the fiercest and best diving knife amongst its competitors. It is well-built, sharp and highly functional, say divers. As it features Titanium construction, the knife is absolutely free from rust.

The only complaint about Argonaut is that you might lose the knife while diving, as the sheath, does not lock the knife. But other customers have stated that the sheath holds it pretty tightly.

Final Impression

If you are looking for a high-grade, robust and ergonomically designed knife, Aqua Lung Argonaut is the best diving knife you could ever have. Even though a little pricey, the knife in itself is very sharp and features quality construction.

Titanium construction is what makes it so durable and corrosion-free. Also, the serrated edge and a smooth edge featured on both sides are sharp and sheer.

Spyderco Atlantic Salt Knife - Best Folding diving knife

Spyderco Atlantic Salt Knife

Spyderco Atlantic Salt Knife is the best folding scuba diving knife in the market if that’s what you prefer. It breaks through the stereotype and comes out as a modern scuba diving knife with its H1 steel construction. Most of the diving knives in the market are made from titanium, but Spyderco gives a little weight underwater with its sleek steel body.

Stern Locking mechanism

One downside of folding knives is that they do not stay put. But, that won’t be the case with Spyderco Atlantic.

The 3.5” of the blade features a 14 mm round eyelet with which you can snap the knife open one-handedly. And, the stern back lock mechanism along with David Boye Dent makes sure to keep the blade locked-up real nice!

The matrix of the metal has been reinforced with nitrogen, so that it holds its sharp edge, does not rust and strengthens with each use. Even though made from steel, Spyderco is completely impervious to corrosion.

Tight Grip

If you look closely, the waffle-like pattern on the handle provides tremendously safe grip, even with diving gloves on. Not to mention, the black nylon handle is injection-molded and is further reinforced with fiberglass for added longevity.

One thing that makes Spyderco Atlantic Salt Knife different from all the other knives is that it comes with SpyderEdge blade (a hollow-ground serrated edge) and no line cutter. A perfect knife to slice through webbing and ropes.

For ease of carrying (tip-up, left or right-side), there’s a black titanium pocket clip provided as well.

Things We Liked

  • ​Allows single-handed operation
  • Sharp and high-strength H1-steel construction
  • Strong grip
  • Rust-free
  • Includes a back lock mechanism
  • Pocket clip and Lanyard hole provided
  • Ideal for rescue situations

Things We Didn't Like

  • ​Does not have a line cutter
  • No buckle straps provided

Customer Reviews

Commercial divers have found Spyderco Atlantic Salt to be the best diving knife in performance as well as durability. It is sharp, does not rust at all, and the texture on the handle almost makes it free from abrasion, say, users.

One disadvantage of using serrated blade is that it is difficult to sharpen. But customers rave about how easy it is to sharpen Spyderco Atlantic. Spyderco offers free sharpening on their products for a lifetime; you have to pay minimal shipping charges. That’s pretty hassle-free!

Apart from that, customers state that the tip is blunted, which makes it safe to use for extraction and rescue, especially in slippery conditions.

Final Impression

The new Spyderco Salt Knife is made of H-1 steel, which stands up to its claim. It is extremely sharp and is not prone to rust. With just a flick of the thumb, the knife opens up to about 8.5”, even with 5 mm thick diving gloves or wet hands. How cool is that?

The waffle grip is strong and secure, the handle offers great control, and the serrated edge is razor sharp. All in all, it is one of the best scuba diving knives, if “foldable” feature is what you seek!

​Promate Scuba Dive Knife

​Promate Scuba Dive Knife

Promate Snorkel Knife is virtually the most low-maintenance scuba diving knife you will ever have. First off, the Snorkel Scuba Dive Knife by Promate comes in 2 versions. One with a sharp tip which is ideal for stabbing, poking, digging. Whereas the safer option of the blunt tip is perfect for less aggressive divers, who don’t anticipate much action underwaters.

Blade Design

The blade is shaped with a standard line cutter as well as a serrated edge. The blade is about 4 ⅜” long, which is just the right size.

On the butt of the handle, there’s a titanium nub provided to be used as a tank knocker and get your dive partner’s attention. The nub is reinforced into a smooth ergonomically-designed rubber handle that gives excellent and most comfortable grip without much slip.

What makes it exciting is that you get to choose one from an array of vibrant colors.

Titanium rust-proof blade excels in strength but demands timely sharpening.

Affordability

For Promate Snorkel Knife, you don’t have to pay more than $55. It is one of the best-selling knives in the market. For this price, you also get a sheath with an adjustable buckle strap to virtually carry it anywhere you’d like and fits most leg sizes.

Things We Liked

  • ​Titanium body is light and rust-free
  • Low-maintenance knife
  • Titanium nub on the bottom
  • Rubber handle gives good leverage
  • Includes a sheath and strap system

Things We Didn't Like

  • ​Difficult to open using one hand
  • The sheath does not hold the knife tightly; Makes noise

Customer Reviews

Customers seem to like the Promate Snorkel all-action Knife. The premium quality blade is sharp, the rubber handle is easy-to-grip, and the titanium nub on the bottom adds to its versatility, say customers.

However, customers have complained about how the rubber might not last more than a couple of years. And, the locking buckle strap system seems to be loose, which is why the knife makes noise when stored in the sheath.

Final Impression

With a titanium blade, Promate Snorkel Knife is quite sleek, sharp and strong, even when roughly used.

Featuring titanium body, this knife will be much lighter than other steel knives when under water. Another key point, the knife is fairly resistant to rust. To provide you with more variety, Promate offers this knife in both sharp as well as blunt tip models.

​PROMATE Barracuda Knife

PROMATE Barracuda Knife

If reasonable price yet high-end scuba diving knife is what you are looking for, have a look at this Promate Barracuda Knife. Just like Promate Snorkel knife mentioned above, this Barracuda model also features a line cutter, a sharp tip, a flat blade and a serrated blade.

As compared to above Promate model, the handle on this Barracuda is far thicker and more ergonomic.

Easy to clean

You can easily disassemble this knife for thorough cleaning and maintenance. The stainless steel blade here has an extra thickness, and Barracuda is one of the sharpest knives on this list.

All the materials used to build this knife are of high-quality and feature a matte finish. When you mount the Barracuda on your ankle, there will be no unnecessary glinting or shine on this knife to attract dangerous predators underwater.

Design Aspects

The handle is ergonomically designed to be comfortable with right grooves. The blade on Barracuda is made from 304 stainless steel. Moreover, there’s also a stainless steel hammer on the bottom that adds to its functionality.

Handling

With Barracuda knife, you will get a quick-release adjustable strap system and a sheath for secure storage.

Promate offers you eight different color options in Barracuda model to pick from.

Things We Liked

  • ​Very sharp blade
  • Hammer included on the bottom
  • Easy to disassemble and clean
  • Strong construction
  • No glinting parts; All parts have a matte finish

Things We Didn't Like

  • ​Straps are facing backward; Notches dig into your skin
  • Catches rust after some time

Customer Reviews

Customers have loved how low-priced Promate Barracuda is, yet does not disappoint you. It is hands-down one of the best diving knife packed with incredible features, say users.

Divers have appreciated the serrated and flat edge razor-sharp blade that works remarkably well during diving adventures. Some users have also liked how Barracuda snugly locks into the sheath with the help of a friction lock.

Final Impression

The Promate Barracuda diving knife is one of the most affordable and sharp-edged swords on this list. At this price, you get stainless steel construction along with flat as well as serrated edges to serve all cutting needs.

What makes it unique from other knives is that you can completely disassemble the knife to make it's cleaning a breeze! Besides, the hammer feature provided on the Barracuda is just cream of the crop.

​Atomic Aquatics Ti6 Dive Knife

​Atomic Aquatics Ti6 Dive Knife

Atomic has achieved notable popularity due to its Aquatics Ti6 knife model. It has bagged-in several positive reviews in just a short period. No doubt, by the looks of it, the Ti6 is a well-made knife that won’t fail to charm you with its performance!

Quality Construction

The 4 inches of titanium knife comes with a heavily serrated edge, a smooth edge as well as a large line cutting notch for versatile use. The handle on the knife is precisely grooved to offer firm and secure grip.

For hassle-free cleaning and maintenance, you can unscrew the titanium pommel, and the knife can be fully disassembled.

Locking Sheath

When not in use, you can lock up the knife in the lightweight sheath provided. The sheath has a push-button release and quick-adjust straps for the convenience of use. You can mount this sheath onto a BC strap or on your calf as well.

Weighing just about 4 ounces, the Ti6 is a pretty robust full-sized knife but is not ideal for heavy-duty cutting applications.

This knife is made available in blunt as well as sharp tip blade options. Seeing its functionality, Ti6 will work ideally for new as well as advanced divers.

Things We Liked

  • ​Rust-free Titanium 4” blade
  • Serrated edge, line cutter and a straight edge
  • Extremely sharp
  • One push button release system of the sheath
  • Titanium butt

Things We Didn't Like

  • ​It is sharp but not razor-sharp

Customer Reviews

Divers have found Atomic Aquatics Ti6 to be well-designed and of good quality. Nothing feels cheap here. Ti6 is a perfect tool for line cutting and piercing purposes. Apart from this, customers have loved how its quick release feature works flawlessly. The sheath and straps are snug and secure as well.

Final Impression

Atomic Aquatics Scuba Diving knife is fairly resistant to corrosion and features a full tang titanium blade. It comes with two types of blade styles: Sharp and Blunt. Use your discretion and choose any one of these. Both the styles come with a serrated edge, a smooth edge and a line cutting notch for multi-purpose use.

If you don’t want a large-sized knife but also don't want a tiny knife, this 4” of Aquatics Ti6 is just a perfect option for you.

Things to look for in Best Diving Knife

Unlike a regular knife, dive knife is supposed to be versatile and work great underwater, even when the diver’s hands are wet or while they’re wearing thick gloves. Which is why you need to consider following factors before making your final decision on the purchase:

Blade material

The durability of your scuba diving knife considerably depends on the type of material used to forge its blade.

Generally, titanium and stainless steel materials are used to shape diving knives, because of their high ability to fight corrosion.

  • Titanium:

Titanium dive knives are known to be 100% rust-proof. This is because titanium is free from carbon needed for oxidation.

Due to this sole reason, titanium knives demand little-to-no maintenance. Besides, they are lighter, stronger and holds its edge well as compared to stainless steel knives.

Seeing all these capabilities, you will find that titanium dive knives are highly priced in the market.

On the downside, titanium might be a little hard to sharpen than stainless steel.

  •  Stainless steel:

Stainless steel is known to rust at a slower rate as compared to steel. Diving knives constructed from stainless steel require simple maintenance process. After each dive, you need to wash your knife with freshwater and let it dry completely. Only when dry, you can store it in its sheath.

Stainless steel knives come with 300s or 400s series alloys. What is that exactly? Lower the series number; greater will be its rust resistance.

By that logic, the 300 series is more resistant against rust as compared to the 400 series. But one disadvantage of 300s alloys is that they do not hold their edge well.

As compared to titanium, stainless steel tends to erode to some extent, solely because of their carbon content.

  • Ceramic:

The latest material used for diving knives nowadays is ceramic, which is corrosion- resistant and extremely sharp. But, because ceramic is not as flexible as metal, its usability is only limited to line cutters.

So if you're looking for an affordable and rust-proof line cutter knife, go for ceramic blade material.

Size of the knife

If you are just a beginner, a compact dive knife with 2” or 3” of blade size will be enough for you. It will effortlessly fit anywhere and will be useful in cutting through sticky hurdles or nets. While choosing a small knife, make sure the handle is long enough for proper grip and control.

For tough jobs, the majority of divers will opt for 4” or 5” of blade size that offers good leverage, high strength, and extreme sharpness.

Extremely long knives (more than 6”) might limit its mobility, especially while scuba diving. So, they are not recommended.

Tip of the Knife

  • For amateur divers, blunt tip knives will work just fine because they won’t get stabbed by the blunt tip while moving around underwater. The blunt tip is good for chiseling, hacking, digging, prying, etc.
  • For professional or experienced divers who love to engage in spearfishing, a sharp pointed tip will be more ideal. Point tip is good for stabbing, puncturing, cutting, etc. Since you won’t be doing that during scuba diving, it is better to opt for a knife with a blunt tip.
  • For recreational divers, a knife with a blunt tip is more recommended.

Edge of the Knife

Most of the scuba diving knives will feature either a straight front edge, a serrated edge or both.

  • For recreational dives, a serrated edge will be helpful to slice through tough obstacles (like natural fibers, kelp, etc.) and it holds its sharpness very well.
  • Non-serrated blades are ideal for cutting through fragile hurdles like vegetation, plastics, etc. But, they are likely to lose their edge with repeated use.

Sheath and Strap System

While underwaters, you would want to strap your knife onto your leg or arm. But, such placement is more likely to get entangled with something underwaters. Most popular placement option nowadays amongst divers is on the BCDs. This way you won’t lose your knife, and it will be much easier to reach.

You can even mount it on your dive belt. The condition is that it should feel comfortable and must be within easy reach.

Almost all of the diving knives come with a sheath. Just make sure you choose the one that allows easy withdrawal, holds the knife tightly and does not feel cheap. If the knife fits loosely or falls off the sheath, it can create a problem while diving.

Now talking about the strap system, some sheath has a strap-buckle system included, whereas others don’t. Look for the strap system that is made from double-stitched nylon for high durability.

Handle Butt

The Best diving knife is the one that features a metal handle butt (either titanium or Stainless steel) to be used as a hammer or a knocker to grab your fellow diver’s attention.

Line cutter notch

A line cutter notch (it's like a small sharp groove) in the knife which allows you to hook a fishing line and cut it smoothly. Try to look for a knife with this line cutter feature, it's certainly worth it and will help you a great deal in rescue situations.

Blackened Blade

Blackened blade and matte knife parts are a must if you don’t want to grab unnecessary attention from the predators of marine life.

Shiny and glistening knives might both scare away as well as attract marine life creatures.

Grip

The handle needs to be ergonomically designed to promote strong, secure and comfortable grip. You don’t want a knife that’s slippery to handle, especially beneath the waves.

Type of Blade

The Best diving knife might have a built-in fixed blade or a foldable blade. Which one to choose?

  • Diving knives with a fixed blade are ideal for single-handed operation. Such knives usually come with a sheath for easy storage.
  • Diving knives with a folding blade are light in weight and small in size. Most of them can be locked when snapped open to prevent injuries. Such knives are generally difficult to open single-handedly and even more difficult if wearing gloves.

Disassembling

If you decide to buy a stainless steel knife, make sure it allows complete disassembling for easy cleaning. That’s because, SS knives are prone to accumulate rust in edges, corners and the area where the handle meets the blade.

Often, you might not even notice, but rust tends to grow underneath the handle, thereby weakening the blade. You might be under the impression that your knife is in good condition, whereas in reality, it might break anytime.

FAQs 

Q. How to maintain dive knives?

Make sure you follow these steps and your knife might hold its edge well and last longer.

  • After every dive session, clean it with fresh water. Remove accumulated salt from different parts and handle, if any.
  • If the handle is removable, disassemble it completely for thorough cleaning.
  • Let it dry completely. Wipe the metal parts and blade with a soft cloth to remove any possible stains or rust.
  • Apply a thin layer of silicone lubricant and then place it into the sheath.

Q. Which material to choose- Titanium or stainless steel?

It depends on your preference. Each material has its pros and cons. Both titanium and stainless steel are highly resistant against corrosion, which is a “must-have” feature for scuba diving knife as it will remain underwater in a salty environment for hours.

  • Stainless steel is softer. That is why it is easy and quick to sharpen its blade. But, they do not hold its edge well, so you need to sharpen them more often. As compared to titanium, they are a little less rust-resistant. But, they are also very affordable in price.
  • Titanium is strong, yet very lightweight. It takes time and effort to sharpen titanium blades, but they hold its edge very well and for a long period.

If you’re worried about the heavy weight of the knife or its maintenance, opt for a titanium blade model.

Q. Which one to choose- Blunt Tip or Point Tip?

It depends on how you are going to use the diving knife.

  • If you are looking for a versatile diving knife to be used as a tactical tool, choose a blunt tip. You can use it for prying as well as cutting. Not just that, if you are going to perform any maintenance diving, for example, underwater welding or boat cleaning, a blunt tip has to be your ultimate choice!
  • For sports diving such as spearfishing, a pointed tip will be your way to go!

Conclusion

Even if you are a recreational diver or are new to diving, you still got to have a reliable and good diving knife. When scuba diving, you need to carry every essential gear as a precaution. And, dive knife is one of it.

Almost all of the dives are performed in salt water, which is why you need to have a knife that’s corrosion-resistant.

When under waters, your mobility is pretty limited. And so, you need to have a knife that performs its task precisely and not worsens your condition. Selecting your best diving knife will facilitate you in emergency rescue situations.

Out of all the models that we’ve reviewed, we would conclude that Aqua Lung Argonaut is the best diving knife so far. Why? Because it is made from 4 mm thick titanium which is missing in all the other models.

Not to mention, its black EDP coating, 7’ long parachute cord wrapping, thick aircraft-grade Kydex sheath and serrated/straight edges tremendously add to its functionality.