The Titanium Dive Knife: A Spearfishing Necessity

By David Fialkoff •  Updated: 10/19/20 •  8 min read

There’s something about the underwater world that keeps pulling us back. It’s an alien environment, presenting thrills and challenges that make us feel alive. It allows us to become one with nature and to witness breath-taking beauty first hand. In the US alone, there are an estimated 3.5 million divers, 11 million snorkelers, and over 2 million spearfisherman and women.

Some disciplines require more equipment than others (one of the attractions of freediving is that you can’t need much to get started). But one piece of kit that is often overlooked is the dive knife. To some divers, it’s not really a priority. However, investing in a good quality dive knife is essential. And if you’re going to invest in one, it is worth spending the extra to buy a titanium dive knife.

Why Carry A Titanium Dive Knife?

Defense

First off, Hollywood has a lot to answer for, along with sensationalized press reports about shark attacks. Most divers will never encounter ‘monsters from the deep’ and be forced to grapple with them in a fight to the death. Attacks do happen, but they are extremely rare. In some cases, a knife has been used to successfully fend off such an attack. But striking an effective blow underwater is difficult and unlikely to prove effective. Also, introducing blood to the water when there’s a bunch of predators hovering around may not be the wisest course of action.
So, let’s get this straight – your knife is a tool, not a weapon.

Having said that, the feel of a solid blade strapped to your arm or leg during your dive does give you a sense of protection – you know it is there if or when you need it. Remember though, the best thing to do is to avoid such a situation if at all possible.

So, if not for fighting off ‘great whites’, what is your knife for?

Safety

One of the most important factors of any form of diving is safety. Yes, it can be a bore having to do all the checks and to continually be aware of all the hazards. But surely it’s worth it? You will minimize the risk, meaning that you and your buddy can dive safely. Anyone who has been on a dive and suddenly found themselves tangled in kelp will know that sense of panic that threatens to overwhelm them.

Likewise, discarded fishing lines, ropes, and nets can present a serious problem, to humans as well as aquatic life in general. In both circumstances, divers have tragically lost their lives, being unable to free themselves in time. This is more of a problem with freediving and snorkeling, but even scuba divers can be caught out. Having an oxygen tank will not be of much use if you start to hyperventilate when tangled in a line. Panic induced by hyperventilation can cause ‘tetany’, which is basically spasms or cramps. And this causes a cycle of panic that can lead to the regulator falling from the diver’s mouth, which could be fatal.

A good, sharp titanium dive knife could free you from a situation like this in seconds.
And if you do spot a sea creature struggling in one of the growing numbers of discarded fishing lines that blight our shores, be sure to set them free.

Communication

It may seem an odd one, but potentially lifesaving! Underwater communication is notoriously difficult. It is easy to become distracted by all the wonderful things you are encountering on your dive. Or you may be so focused on your task that you fail to see your buddy waving frantically to alert you to a potential emergency. A sharp rap on a metal surface (such as an oxygen tank) with a metal blade makes enough noise to get someone’s attention.

A quick, clean kill

For spearos, dispatching your freshly caught prey is an ethical and humane thing to do. Most spearfishers will not relish the thought of prolonging the pain and suffering of any creature. A sharp knife is essential for this task. This means that the knife will need a sharp tip. Those with blunt tips are recommended for Scuba diving as it lessens the risk of accidents. As a compromise, tanto tips are available, which are a combination of both; a sharpened end for cutting, with a blunted tip at the very end.

Why Should I Get a Titanium Dive Knife?

The debate as to whether titanium or stainless steel blades are best has been raging for many a year. Almost as long as the one as to whether you need a knife at all. As for this last argument, anyone who believes they don’t need one usually changes their mind pretty quickly after a close call with a fishing line/rope/kelp/any kind of marine garbage that ensnares them. But back to titanium vs stainless steel.

To be fair, most of the good quality stainless steel knives out there are just fine. They do the job when required. So why would anyone pay more for a titanium knife? Let’s examine the evidence.

Strength

Most people who are reluctant to invest in a titanium dive knife are basing their opinion on the fact that it is more brittle than steel. And this is true. But these knives are made from titanium alloy. In this form, the titanium is far stronger, taking all the best qualities of the other metals to produce a greatly improved material. The flexibility of the end product makes them less likely to break than a steel one. Some divers even use their titanium knives to open shellfish.

Rustproof

As it contains little or no carbon (which reacts with seawater to cause oxidization), it is completely resistant to corrosion and will never rust, and therefore requires less maintenance. However, you should always keep it in good condition to prolong its life. While it won’t need rinsing, it’s a good idea to do so anyway, and to oil the blade before storage.

Lightweight

When you’re underwater and in a potentially dangerous situation, you don’t want to be fumbling with a heavy piece of razor-sharp metal. Titanium dive knives are up to 60% lighter than their stainless steel counterparts. They can be whisked out of their sheath quickly and put to use in seconds.

Also, a heavy blade can be a drag (literally) on a long dive. Whether attached to your arm or leg, you’ll start to feel it after a while.

Sharpness

A touchy subject when it comes to the titanium vs stainless steel argument! High-grade steel helps in the fight against corrosion but loses its edge quickly and needs regular sharpening. Knives with higher iron content keep their edge longer but are prone to rust. Titanium knives, however, are essentially rustproof. Opinions vary as to their sharpness but most people feel that you can never get them as sharp as steel. That’s not to say that they are inferior in any way, or that it won’t serve you well when you need it. Most will be wickedly sharp when you buy them and will stay that way for years – though a lot will depend on use. This subject, though, will largely come down to personal experience. Most divers who choose a good quality titanium dive knife make a solid investment that lasts them a lifetime. If they do require sharpening it is probably best to get it done professionally. You can tackle the job yourself (using a diamond rod sharpener, for example) but there’s a fair chance you’ll do more harm than good.

In Conclusion

A dive knife is regarded by most responsible divers as a vital piece of equipment. It is no exaggeration to say that your life, or that of your dive buddy, could depend on it. You need one that is reliable, sharp, easy to use, and easy to maintain. For all these reasons, a titanium dive knife is ideal. In fact, it is recommended by some veteran divers that you invest in two. In the event that you can’t reach one, the other will be accessible.

They need not be massive – it isn’t a case of ‘biggest is best’! A large knife will be cumbersome and more of a hazard than anything. Short blades between 2 – 5 inches are perfect for the job. Make sure they have multiple uses; a serrated edge for obstacles like kelp and rope, a line-cutting notch for slicing easily through fishing line, a straight edge for cutting through plastics and nylon. Some divers go for a black blade to minimize the risk of the reflection scaring off sea creatures.

So, choose your knife (or knives) wisely. And consider investing in a titanium dive knife for all the reasons stated above. Yes, they’re more expensive, but the benefits are clear. A dive knife is a tool that you may not even use much, but it’s comforting to know that it is there when you need it.

It’s an investment that just might save your life.

David Fialkoff

David Fialkoff is the founder of Spearfishing.Live, a site that's dedicated to the sport of spearfishing. He is a full-time digital marketer and loves to spend time chasing fish underwater on the weekends.