While you may not use it on every dive, having the right dive knife is just as crucial as some of your other scuba diving gear. From freeing yourself from entanglements to cutting fishing lines, this small yet essential tool could make all the difference in an emergency situation. In fact, it’s important to understand that you should never dive without one.
There are a number of important factors you need to consider when choosing your dive knife, from the type of material it’s made from to its size. To help you through this crucial consideration, we have put together this complete guide to choosing the right knife for scuba diving.
What Are Dive Knives Used For?
As we have touched upon, your dive knife will primarily help you to deal with underwater entanglements, such as cutting through fishing lines and nets or removing obstacles from dive sites. You might also find that you use your knife for a range of general uses too, like gear maintenance when no other tools are available. Ultimately, having a dive knife on hand ensures that you’re prepared for unexpected situations that could otherwise become dangerous if you were to be poorly equipped.
Dive Knife vs. Line Cutter - What Is The Difference?
When shopping for a new dive knife, you might also come across a range of line cutters and understanding when one is more appropriate than the other is key to both choosing the right one for you, and for keeping you safe. While both tools serve a similar purpose, the key difference is in their design and usage.
A dive knife is the more versatile of the two tools and will often feature at least one sharper blade like a cutting edge or serrated edge, as well as a built-in line cutter. A line cutter, on the other hand, is a smaller, safer, and more compact option designed specifically for slicing through lines and fishing nets with minimal effort. Line cutters are also frequently used to remove themselves or their dive buddies from equipment in case of an emergency, especially as they have a harness without shoulder buckles. In these scenarios, a line cutter blade is much better at quickly and efficiently cutting through webbing.
Key Dive Knife Features
The dive knives you can choose from probably won’t look that different to the naked or untrained eye, but they can actually vary vastly when it comes to the different features they possess. Look out for the following to find one that suits your diving needs:
Blade Types
Dive knives typically come with a straight edge, serrated edge, or a combination of both. A straight edge is excellent for making clean and precise cuts, such as slicing through softer ropes and lines. A serrated edge, on the other hand, is better suited for sawing through tough materials like thick ropes, fibrous kelp, or plastic where a little more force is needed.
You’ll also encounter many dive knives with a mixture of both! These combination blades offer exceptional versatility, and ensure you’re primed for all conditions and hazards.
Knife Size
The size of your dive knife can hugely affect its functionality and the ease of use underwater. Often it’s easy to assume that larger knives are better, with stronger and longer blades, but they can also be cumbersome, create unnecessary drag, and may be difficult to store securely. A compact knife may be easier to mount on your BCD or attach to a hose, but possibly at the expense of some durability and ability to cut through the toughest obstructions.
Materials
Most of the dive knives you’ll come across and use will be made from stainless steel, offering impressive sharpness, ease of sharpening and good levels of corrosion resistance. You can also buy titanium dive knives, which typically feel stronger and are even more corrosion resistant, but can be much harder to sharpen.
Whichever type of metal you do choose, it’s important to bear in mind that you will need to clean and maintain your dive knife on a regular basis. Salt water can quickly degrade the surface of the knife if it’s not washed frequently.
Mounting Style
Lastly, it’s important to think about where you plan to mount your dive knife. This is an important decision as it makes a huge difference when it comes to how quickly you can access your safety tool in an emergency. However, there is no one-size-fits-all answer; how you choose to mount your knife will largely depend on the dive environment and your own comfort.
Traditional, leg-mounted dive knives are particularly popular among those who prefer a larger and tougher blade, but they can be awkward to grab in an emergency. Mounting your knife on your BCD, hose or even wrist can allow for quicker access in situations where movement is restricted, such as wreck diving.
Aquanauts' Dive Knife & Line Cutter Picks
Once you know what to look for from your next dive knife, and which features will be particularly useful to your type of diving, it’s time to pick yours. At Aquanauts, we stock a complete range of the most popular dive knives and line cutters available right now from brands including Scubapro, Beaver and Cressi. Some of our top picks include:
Beaver Cutlass
Our first dive knife pick is the superb Beaver Cutlass. This robust and versatile dive knife is a great all-rounder, with a large 14cm blade with half serrated edge, half straight edge, and line-cutting notch to ensure you’re equipped in all circumstances. What we particularly appreciate about the Beaver Cutlass is its reliability, with a snap lock solid plastic sheath and heavy-duty quick-release straps to ensure that the blade bulk isn’t a hindrance in an emergency.
Beaver Discovery
For those who would prefer a more compact dive knife, the Beaver Discovery is a top choice. Again, this Beaver dive knife combines straight, serrated and line cutter functionality but in a smaller, 11cm blade great for wrist or BCD mounting. Where this dive knife really comes into its own, however, is its multi-use capabilities. The blunt tip adds a full range of different tool functionalities, remaining strong and durable thanks to a stainless steel construction.
Beaver Ranger
Our last dive knife pick is the Beaver Ranger, which is another 11cm blade option but with the more traditional pointed tip. This offers a longer straight edge for advanced cutting ability, all without losing the critical serrated edge and line cutter on the back side. It’s easy to mount, with heavy-duty straps included as standard.
Cuthero Ceramic Blade
When it comes to line cutters, you can’t get much better than the Cuthero Ceramic Blade line cutter. Available in 4 colours, the ceramic blade is incredibly durable and strong, giving you peace of mind that it can cut through almost anything in an emergency. This Cuthero line cutter also comes with a handy storage pouch, making storage seamless.
If you have any questions about these or any of the other dive knives available at Aquanauts, don’t hesitate to get in touch with us. Our expert team of divers is always on hand to give you a hand and help you select the right knife for your diving adventures.