Garth loves camping under the stars with his Arb III, scuba diving, snorkeling, and also tanning. His favourite snorkel spots include Alanya (Turkey), Koh Rong (Cambodia), and Maui (Hawaii, USA).
He also loves to visit the cenotes in Mexico and he recommends everyone reads the book, “The Soul of an Octopus”, because, he says “they are sensitive, just like me”.
Hey guys! Today we’re going to take a look at the best scuba dive knives for 2020, but first, we’ll briefly discuss a few definitions and provide some context before we jump into our full guide, followed by editor picks.
Off the top, we feel it’s important to say that you don’t want to sacrifice practicality for function, as tempting as it may be.
Many people will buy a dive knife based on style, and that’s fine, but if it’s at the expense of a more practical reason, then perhaps it isn’t a good idea to make such a sacrifice.
Luckily, there are plenty of dive knives that combine function and style perfectly so there’s no need to sacrifice anything, per se.
Below, you’ll find a table of contents that lays everything out for you. Check it out and click where you want to go in the article to read more about it.
Table of Contents:
- Scuba Diving vs. Free Diving
- Why do people scuba dive?
- Dangers of scuba diving
- Best dive knife for beginners
- Characteristics to look for in a good dive knife
- Best fixed blade dive knife
- Best folding dive knife
- Best pointed tip dive knife
- Best blunt tip dive knife
- Best dive knife for spearfishing
- Best dive knife for shark attacks
- Best dive knife for self-defence
- Best dive knife for rope-cutting
Let’s dive in!
Scuba Diving vs. Free Diving
Scuba diving is an underwater sport where the diver must use underwater breathing equipment (scuba) to breathe.
The main difference between scuba diving and freediving is the breathing mechanism. Freedivers hold their breath throughout the entire dive.
Scuba divers, on the other hand, must never hold their breath to prevent the risk of lung over-expansion. The breathing equipment serves to maintain safe ascent rates and no-decompression limits.
In freediving, diving gear like wetsuit, snorkel, and fins are not mandatory. In scuba diving, you must have this and a lot more, especially protective gear.
A scuba diver moves underwater by the help of fins attached to their feet. However, extra propulsion can come from a diver propulsion vehicle or a sled pulled from the surface.
Now, you might wonder, why would someone do one or the other? How similar is freediving to scuba diving, actually?
Here’s a great video which asks the eternal question – Scuba Diving VS Freediving – Which is better? This is a great introductory video to explaining some of the differences in both practice of each activity, and why someone would want to do one or other. Worth a watch!
The main takeaway from this video is this, we think – freediving and scuba diving are two different activities, as he says, with skills that are not specifically transferrable to one another. Just because you are good at one, doesn’t mean you will be good at the other.
They are very similar in that they both include diving into water, but there are many differences between them as well. Let’s move on, because we are here more to discuss scuba than freediving, as well as spearfishing.
Why do people scuba dive?
One of the reasons why people engage in scuba diving is for recreational purposes. The scope of recreational scuba diving doesn’t physiologically or physically limit when a diver should end the activity.
You’ve probably looked up videos on scuba diving before to see what it’s like, if you’ve never done it before, but here’s a quick video to show you, more or less, the reason to go scuba diving – it’s beautiful down there!
See? It’s no wonder so many people are interested in this activity. It’s like going to another world, almost literally speaking.
To summarize briefly, recreational diving encompasses some of the following reasons:
- Tourism and sight-seeing in a variety places undersea
- Extreme sports aspect where divers test their limits in challenging conditions
- Underwater life observation
Scuba divers also engage in the sport for professional purposes. This is where the divers are paid for their work underwater.
Sometimes, if the research involves even deeper dives, it may require a submersible, such as this one here:
Pro scuba divers who do it in the name of science have a hazardous occupation that is regulated by legislation and codes of practice. The diver must work as a member of a team. Some professional scuba diving applications include
- Inshore civil engineering
- Marine salvage
- Military services
- Public safety roles
- Scientific research
- Ships husbandry
- Law enforcement
Anyone who wishes to become a professional diver must undergo specific training that satisfies regulatory agencies with regional or national authority.
By this point in the article, you can begin to imagine some reason you might need a dive knife. Well, keep reading as we get into the dangers of scuba diving presently.
Dangers of Scuba Diving
Scuba diving is enjoyable, but it does come with some risks.
Among them is decompression sickness that is caused by the absorption of excess nitrogen by the body tissues.
This results by descending too fast underwater where the pressure is higher than on the water surface.
The absorbed nitrogen leads to the formation of bubbles in the tissues. The result is a painful condition that can cause nerve and tissue damage and sometimes death.
This video explains it quite well…
Most of the undersea creatures are not harmful to divers. Most importantly, you should learn not to touch any animals or corals to avoid the risk of causing harm to them and yourself.
However, you never know when you’ll come across the aggressive types of sea animals. They might attack you even without you approaching them.
Here’s a guy that runs into a croc underwater. This is just one example of a creature you might come face to face with, depending on where and when you dive.
For your safety, you need to be well equipped by carrying protective scuba diving equipment such as the diving knives we’ll soon be discussing.
Scuba diving calls for proper preparation. Part of this is ensuring that you acquire all the right scuba diving tools. Among them, most assuredly, is a high-quality dive knife.
These can also be used for spear-fishing and a multitude of other water-related applications.
Our Guide to Dive Knives for Scuba and Spearfishing
A dive knife is a tool that scuba divers use to disentangle themselves from fishing lines or nets, among other things.
Sometimes, the divers use them in emergency cases to tap on their tanks to get the attention of their partners. Other applications include spearfishing when the situation allows.
Here’s a video of a situation which requires a dive knife to get out of, where a line gets tangled Maybe you’ve been in a similar situation, or, if not, it’s something to be aware of.
This is part of the reason why divers carry such knives to begin with – to get out of potential life-threatening scenarios like this.
The price of a dive knife will ultimately determine your purchasing decision. In most marketplaces (online or in real life), you can get the best dive knife for under $50, but this is just a ballpark figure and of course changes constantly so remember that.
Take note that dive knives are not meant to be brandished weapons and should never be used to cause harm to aquatic life or damage the underwater environment intentionally, despite the fact that some of them look fairly Rambo-esque.
Knowing how to choose the best dive knife is crucial for a diver, whether a beginner or a professional. If you’re looking to learn how to choose the perfect one for you, you’ve come to the right place.
For each specific type of knife, we choose a favourite and explain why it is one you should strongly consider if you are going to be making a purchase.
Choosing the right dive knife for a beginner
When looking for a dive knife for the first time, there’s much you need to know. A dive knife should be customized to your preferences when diving, and should be able to do what you require of it.
One thing you may want to ask yourself if you’re just getting into diving and require a knife is, where will you be diving first? And, once you know the answer to that, you should start to do a bit of research on what the diving is like there, in terms of conditions, what creatures you may encounter there, and any other relevant details.
Also, by this time, you’re wondering why you specifically need a dive knife and not an ordinary knife. What’s the difference, anyway?
As with most useful tools, the difference between your garden variety knife you might use for hunting and one you’d take with you diving is very much in the details.
There are some key characteristics to look out for, as we’ll talk about below.
Here are the characteristics to look for in a good dive knife, some of which are exclusive to these types of knives:
1. Knife Material
The material that makes the knife will largely determine its performance and longevity. Dive knives are usually made from either titanium or steel.
Advantages / Disadvantages of Titanium Dive Knives
Titanium knives are very light in weight and very sturdy. Titanium alloy is corrosion-resistant, which makes the knives maintenance-free.
On their downside, titanium knives are expensive and hard to sharpen.
Advantages / Disadvantages of Stainless Steel Knives
Stainless steel knives are very easy to sharpen but call for a lot of maintenance in keeping corrosion away. After every dive, they must be washed with fresh water and be completely dried before storing them away.
Stainless steel knives come in 300 and 400 alloy types. The 300 alloy is more resistant to corrosion but requires more sharpening. The 400 alloy has a better edge resistance but is more prone to rusting.
Advantages / Disadvantages of Ceramic Dive Knives
Ceramic dive knives are a lot more brittle than their steel and titanium counterparts. Their good side is that they achieve a higher level of sharpness. However, they’re only a great choice if you intend to use them for cutting but not for prying or digging.
2. Edge of the Blade
The edge of a dive knife can be either straight or serrated. A straight blade is more appropriate for cutting things like nylon ropes and plastic. The serrated type is best used for sawing through natural fibers or kelp.
The best thing is to look for a dive knife with both a straight and a serrated edge instead of having two separate ones.
3. Tip of the Blade
The tip of the blade can be sharp, blunt, or tanto (pictured below).
A blunt tip is best if you don’t intend to use the knife for stabbing or piercing. It’s a lot safer than the sharp-tip knife and prevents you from accidentally puncturing the hoses. A blunt tip knife can also be used for digging, chiseling, and hacking.
A sharp tip is more popular among divers who are interested in spearfishing. It provides for easier spiking of the fish and finer cuts. Since they pose a higher risk, a sharp-tip knife should always be carried under a sheath.
A tanto tip knife is a hybrid between sharp and blunt tips. It features a high point with a flat grind, a design that makes it extremely strong, capable of puncturing the hardest of materials.
The downside of the tanto tip knife is that it doesn’t make for a great utility tool. The front edge of the blade meets the unsharpened back edge at an angle rather than a curve, causing it not to have a belly.
So, whether you’re scuba diving or spearfishing, you need a dive knife that can rescue you from entanglements and fierce fish like marlin or amberjack.
Here’s a situation you would wish to avoid – a shark attack.
You never know when a knife will come in handy. You don’t wander into a forest in the Yukon without some kind of weapon.
As for taking an ordinary knife with you, consider that some monofilament lines can be challenging to cut with an ordinary knife.
Besides, dive knife manufacturers understand that it can their function as a truly multi-purpose piece of equipment. Most come with a handle that acts as a hammer when the situation demands it.
The knife blades are mostly black or dark grey. You may also opt for a ceramic dive knife since it’s not reflective, but unfortunately, it’s not as versatile.
Here is a picture that shows a stainless steel blade vs a coated ceramic blade.
The differences between them are not merely aesthetic. Steel dive knives, for instance, are cheaper, easier to sharpen, but also require more care to keep them in working order. There are also titanium knives available.
What else should you look for when buying a dive knife?
Now that you know the features to look for in a scuba knife, is that all? There’s something more you need to check.
In choosing a dive knife, bigger doesn’t always mean better. A more compact tool would be ideal for scuba diving. A large knife is not necessary for recreational diving. Besides, if you carry it on the calf, it may increase the risk of entanglement on its own.
The ideal length of a dive knife should be between 3 and 4 inches, which is enough to cut through the net and also easily fits in your BC pocket.
Ease of Maintenance
Before you buy a dive knife, check to see that you won’t have trouble giving it the necessary maintenance. A general maintenance schedule entails the following.
Before you engage in your diving activities, inspect your knife for rust spots. In case of their presence, use a cleaning solution and cloth to wipe the blade clean. After that, check the locking mechanism on the knife and sheath to ensure it works properly. If need be, lubricate it with silicone.
If possible, disassemble the knife once in a while. This allows you to give the knife a thorough cleaning while removing sand and salt that may have found its way in the inner parts of the knife.
Sharpen the knife if necessary. Do this using a cross-hatched fine metal file as opposed to sharpening on stone. For the serrated blades, sharpening without changing the shape is a lot more difficult. Use a sharpening rod for the serrated edges.
After each dive, always rinse the dive knife with fresh water and scrub to remove debris and salt. Dry it thoroughly and coat the blade with silicone grease.
Here’s a great how to video we enjoy about dive knives and some overall tips that you will appreciate if you are a beginner.
Now, we will look at fixed blade knives…
Fixed Blade Dive Knives
Dive knives come with two types of blades. They can either be fixed or foldable.
Knives with a fixed blade are considered to be more reliable as they are easier and more convenient to use with one hand. Their application includes self-defence and spearfishing. They also come with a sheath for safe storage.
Knives with a foldable blade have the advantage of taking up less space and are also safer to carry. They are mostly used for disentanglement from fishing nets and ropes. Their only challenge is that they’re not easy to use with one hand.
The knives come packed in a solid sheath for safe storage and also keep the knife close to you.
Folding Dive Knives
This is the safest type of knife when it comes to spearfishing. It’s more compact, lightweight and can easily be stored in the BDC pocket.
A folding knife is ideal for scuba diving, but unfortunately, they don’t work well with water because the moving parts can get corroded.
It’s a compact knife that has several locking mechanisms. However, it’s not convenient to open it with only one hand.
An example of a folding dive knife is the Spyderco dive knife. It comes with a warranty so you can be sure it’ll last for many years.
As you spearfish, you’ll come across various dangerous predatory fish.
A dive knife with a pointed tip will help you protect yourself by killing it humanely without much suffering.
Check out this video where a spearfisher catches a Black Marlin. These are fish you don’t really want to mess with, and a knife is a necessity in a situation like this.
Next, we talk about blunt tip knives.
A pointed dive knife can sometimes pose a danger to your body or damage your wetsuit. With a blunt tip knife, you reduce the chances of accidentally stabbing yourself. It’s also the best type if you need to cut ropes, lines, or clean the boat.
Another factor to consider is the location of the knife. The most popular locations are thigh, ankle, and waist. (when it comes to blunt knives or all knives).
Many scuba divers strap their dive knives to their legs because that’s what professional spearfishers do.
However, if your knife is for emergency purposes, you may not reach your leg fast enough to grab the knife. It may also get tangled up in stuff while on your leg, stripping it of its usefulness.
Wearing a knife on the leg makes more sense when snorkeling. And this is if it’s the only place you can put it if you don’t have a BCD. If you must place it on the leg, ensure it’s in the inner side of the ankle.
A compact knife that you can stash in the BC pocket or BCD low-pressure inflator, strap on your upper arm, or mount on your inflator hose is a better choice.
Putting your dive knife in a BCD pocket provides for a no-frills method of storing and carrying your knife. The risk of entanglement is almost zero, but reaching the knife can be tricky when under pressure.
With a BCD, you can also place the knife on the waist belt like you would any other knife. The secure positioning of the knife on the waist is at the mercy of the manufacturer. However, there’s a lower risk of entanglement and putting the knife back in position isn’t too much work.
As a beginner, knowing which diving knife can be quite a challenge.
Reading through reviews before making a purchasing decision will put you in a better position. It’ll give you information on what to look for when buying a dive knife and why.
Best Dive Knife for Spearfishing
Spearfishing is a fish-hunting activity that dates back to thousands of years ago. It’s a similar activity worldwide, with the only difference being where it is practiced.
The equipment used also differs from place to place, with pole spears and slings being popular in the Bahamas and Bermuda.
Spearguns are common in most other parts of the world, not to mention spearfishing knives. In scuba diving, you’ll be in a better position to use spearfishing dive knives more than other tools.
When buying a dive knife for spearfishing, you’ll need one with a pointed tip so that you don’t miss your target. Consider purchasing the Cressi Skorpion dive knife as it is highly versatile.
You can use it for diving, snorkeling, and spearfishing. As an Italian brand, it has established itself as a quality and revolutionary product.
The back of the knife is serrated, which makes it great for cutting harder materials and sawing. The sharp front edge of the knife also allows you to cut safely through any line. The blade is made from resistant stainless steel that’s also easy to sharpen.
Best Dive knife for Shark Attacks
When you come face to face with a shark while scuba diving, you’ll need to have a protective tool with you.
Among the best dive knife for sharks that you may want to consider is the Atomic Aquatics‘ Ti6 that comes with either a blunt or sharp tip or the blade is 4 inches long and hardly bends or snaps.
While one edge is serrated, the other one is flat. Since the knife is lightweight, it perfectly sits in its sheath but is also quickly released at the push of a button. The straps of the holder are also simple to adjust.
Here is a video which discusses the Tusa Titanium Dive Knife into shark infested waters.
Now, on to more knives about self-defence.
Best Dive Knife for Self-Defence
As mentioned earlier, scuba diving comes with its fair share of risks. You may come across predators while underwater, and you need to be prepared to protect yourself.
The best dive knife for spearfishing may not necessarily be the best for self-defence.
While many brands claim to offer the best defence, you need to be careful when purchasing one. One brand you may want to try is the Promate USA Barracuda Sharp Tip Knife.
It’s exceptionally sharp and comes with both a sharp and serrated edge.
It requires little maintenance to keep it in good shape. The handle provides a good and stable grip so that you won’t accidentally cut yourself on the sharp tip.
The sheath keeps in well locked in place, and since it’s not flashy, it doesn’t attract unwanted attention.
Best Dive Knife for Rope Cutting
The Aqualung Squeeze Diving Knife has been reviewed as the best dive knife for rope cutting. It has one of the best sheath mechanisms, letting you grab the handle and squeeze the tabs to unlock and uncover the knife.
The blade is 3 inches long, is made with stainless steel, and has all the essential features. Its line cutter works excellent and the serrated edge tears through all types of ropes, whether light or medium.
The blunt tip is ideal for chipping away or prying things open.
Here is a video showing the Aqualung Squeeze Diving Knife for more information.
Scuba diving is both thrilling and potentially dangerous, and that’s why you must have the right gear and equipment. Among the tools you need is a scuba diving knife.
You’ll need it for various purposes like disentangling yourself from fishing nets or ropes, self-protection or spearfishing.
Different knives are built for different purposes, and it’s only essential that you know what you want to use it for. This will help you look for the right qualities and design.
If you’re able to find a multipurpose knife, the better equipped, you’ll be.