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Why Get A Dive Knife And How To Choose Yours?

Going scuba diving isn’t going to a warzone but you’ll still need to carry a knife. A dive knife, to be precise. There’s a bit of difference in opinions in the diving community about the usefulness of carrying dive knives. But whether you are an advocate for or not a fan of carrying dive knives, I think you’ll agree with me that it’s better to carry a dive knife and not need it than need a knife and not carry any.

Let’s quickly take a look at the potential benefits of dive knives. For one, they help you cut through any underwater material you may get entangled in like fishing line, kelp, and so on. If you are a commercial diver, a dive knife may aid in your underwater tasks.

You can also signal nearby divers in case of an emergency by banging the dive knife against the metal of your tank. A dive knife will also come in handy in freeing trapped marine life although you should be super careful to ensure you are not putting yourself at risk or harming the animal.

With all these, I think you can see why carrying a dive knife makes sense. I’ve written a little guide t help you see what factors to take into consideration when choosing a dive knife. Let’s go!

Why Do You Need A Dive Knife?

One of the most important benefits of a dive knife is that it helps you through any underwater material you may get entangled in like fishing line, kelp, and so on. Trust me, getting entangled in any of these materials underwater isn’t fun and you’ll need the sharp edge of a dive knife to comfortably free yourself.

Commercial divers will work with a range of tools underwater to perform their tasks and dive knives are usually among these tools. To them, dive knives are an important tool that helps get their jobs done.

While you can signal to nearby divers to get their attention, being able to bang a dive knife against the metal of your scuba tank may come in handy in case of emergencies. A dive knife will also come in handy in freeing trapped marine life although you should be super careful to ensure you are not putting yourself at risk or harming the animal.

Sharp Tip vs. Blunt Tip

Scuba knives either have a blunt tip or a sharp tip (also called a pointed tip). The blunt tip is flat and dulled and is more suited to prying than a pointed tip. As the blunt tip is dulled, it’s safer to use as there’s less risk of you accidentally stabbing your leg or even puncturing your BCD when you want to return the knife to its sheath.

The pointed or sharp tip is very strong and designed for cutting or piercing. People who spearfish will need knives with pointed tips to butt their prey.

There’s also the ‘Tanto tip’ which is a hybrid of sharp tip and blunt tip.

Stainless Steel vs. Titanium Blades

Generally, dive knives are made of stainless steel or titanium, two very strong metals. Stainless steel is corrosion-resistant, has a good cutting edge, and may need to be sharpened from time to time depending on the type used. However, a special type of stainless steel called Marine Grade 316 stainless steel retains its edge for a longer time and has increased resistance to corrosion.

Titanium dive knives have the advantage of being lightweight, super strong, completely resistant to corrosion, and retaining their edge for a very long time. Thus, titanium is the best material for dive knives although it is more expensive.

Straight vs. Serrated Edges

To make dive knives ready to cut through anything underwater, manufacturers usually incorporate both straight and serrated edges on them. Straight edges are more suited for finer cutting tasks and are easy to maintain.

Serrated edges, which feature a series of ‘teeth’ or mini-edges, are designed for tougher cutting operations like stubborn kell fronds or ropes. And serrated edges maintain their sharpness longer than straight edges although they are more difficult to sharpen.

Dive Knife Positioning

The traditional position to put your dive knife is your leg or ankle. The knife sheath is attached to your legs and the knife is placed in it. And when placing dive knives on your leg, put them opposite your dominant hand to give you better control of your movements with the dive knife.

You can also put your dive knife in the pockets or attachments of your BCD. Some BCDs come with spots for dive knives making it easy to attach them. You can also attach your dive knives to the inflator hose for easy access.

Where you mount your dive knife is ultimately up to you but I recommend attaching them to your BCD. This way, the dive knife is safely stored away and out of your way when not in use. And you can quickly retrieve it when you need it.

Other Factors To Consider When Choosing Your Dive Knife

Durability / Corrosion Resistance

Dive knives made of titanium are more resistant to corrosion than those made of stainless steel. But regardless of the metal used to manufacture your dive knife, you need to rinse it in fresh water after a saltwater dive and allow it to completely dry outside its sheath to enhance its longevity.

Sheath

Two options exist to store dive knives and they are sheath or folding the knives. Folding dive knives have a groove in the handle where the knife folds in. You can store them in your BCDs and quickly retrieve them for use.

A sheath is another option to store dive knives and it allows you to attach your knife wherever you want – your leg, BCD pocket flap, or BCD deflator hose. If your knife isn’t self-folding, you’ll need a sheath. You’ll also need a sheath if you want to attach your knives to your leg, arm, or BCD pocket flap.

It’s common to see sheathes with a quick-release button that must be pressed down to release the knife. This way, the knife won’t accidentally get out of the sheath.

Comfort / Grip

The handle of your dive knife should be comfortable and easy to grip, especially if you wear (and you should) scuba gloves. Being able to maintain a firm and steady grip on your knife is key to being able to use it underwater.

How To Travel With A Dive Knife?

In case you are not aware, the Transportation Security Administration (TSA) has strict regulations about sharp objects that can be used as weapons on a plane. But the good news is that you can travel with a dive knife as long as you pack it correctly – the knife should be in a sheath or wrapped carefully around a thick towel.

Also, the knife should be in your checked luggage as the TSA forbids carrying sharp objects that can be used as weapons onboard. Since you’ll be carrying other scuba diving gear, it’s advisable you put your knife and other scuba gear in your checked luggage.

How To Care For Your Dive Knives?

While dive knives are made from strong and durable metals, they still need some maintenance to last long, especially after a saltwater dive. As I said above, rinse your dive knife in freshwater after a saltwater dive and allow it to completely dry outside its sheath to enhance its longevity.

Final Thoughts

I’ll end this article by saying what I said at the beginning of this article – “It’s better to carry a dive knife and not need it than need a knife and not carry any.” Go through this list to select a dive knife and while you may not always need it, it’s better to be safe than sorry!

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